Index

Found 631 pages:

# Page Tags and summary
1 Browser Extensions Add-ons, Landing, WebExtensions
Extensions, or add-ons, can modify and enhance the capability of a browser. Extensions for Firefox are built using the WebExtensions API cross-browser technology.
2 Add a button to the toolbar WebExtensions
Toolbar buttons are one of the main UI components available to extensions. Toolbar buttons live in the main browser toolbar and contain an icon. When the user clicks the icon, one of two things can happen:
3 Anatomy of an extension WebExtensions
An extension consists of a collection of files, packaged for distribution and installation. In this article, we will quickly go through the files that might be present in an extension.
4 JavaScript APIs WebExtensions
JavaScript APIs for WebExtensions
5 alarms API, Extensions, Interface, Needs Privileges, Reference, WebExtensions, alarms
Schedule code to run at a specific time in the future.
6 alarms.Alarm API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, alarm, alarms
Information about a single alarm. This object is returned from alarms.get() and alarms.getAll(), and is passed into the alarms.onAlarm listener.
7 alarms.clear() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, alarms, clear
Cancels an alarm, given its name.
8 alarms.clearAll() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, alarms, clearAll
Cancels all active alarms.
9 alarms.create() API, Add-ons, Create, Extensions, Method, Non-standard, Reference, WebExtensions, alarms
Creates a new alarm for the current browser session. An alarm may fire once or multiple times. An alarm is cleared after it fires for the last time.
10 alarms.get() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, alarms, get
Gets an alarm, given its name.
11 alarms.getAll() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, alarms, getAll
Gets all active alarms for the extension.
12 alarms.onAlarm API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, alarms, onAlarm
Fired when any alarm set by the extension goes off.
13 bookmarks API, Add-ons, Bookmarks, Extensions, Interface, Non-standard, Reference, WebExtensions
The WebExtensions bookmarks API lets an extension interact with and manipulate the browser's bookmarking system. You can use it to bookmark pages, retrieve existing bookmarks, and edit, remove, and organize bookmarks.
14 bookmarks.BookmarkTreeNode API, Add-ons, BookmarkTreeNode, Bookmarks, Extensions, Non-standard, Reference, Type, WebExtensions
An object of type bookmarks.BookmarkTreeNode represents a node in the bookmark tree, where each node is a bookmark, a bookmark folder, or a separator. Child nodes are ordered by an index within their respective parent folders.
15 bookmarks.BookmarkTreeNodeType API, Add-ons, BookmarkTreeNodeType, Bookmarks, Extensions, Property, Reference, WebExtensions
The bookmarks.BookmarkTreeNodeType type is used to describe whether a node in the bookmark tree is a bookmark, a folder, or a separator.
16 bookmarks.BookmarkTreeNodeUnmodifiable API, Add-ons, BookmarkTreeNodeUnmodifiable, Bookmarks, Extensions, Non-standard, Reference, Type, WebExtensions
The bookmarks.BookmarkTreeNodeUnmodifiable type is used to indicate the reason that a node in the bookmark tree (where each node is either a bookmark or a bookmark folder) cannot be changed. This is used as the value of the bookmarks.BookmarkTreeNode field on bookmark nodes.
17 bookmarks.create() API, Add-ons, Bookmarks, Create, Extensions, Method, Non-standard, Reference, WebExtensions
Creates a bookmark or folder as a child of the bookmarks.BookmarkTreeNode with the specified parentId. To create a folder, omit or leave empty the bookmarks.CreateDetails parameter.
18 bookmarks.CreateDetails API, Add-ons, Bookmarks, CreateDetails, Extensions, Non-standard, Reference, Type, WebExtensions
The CreateDetails type is used to describe the properties of a new, bookmark, bookmark folder, or separator when calling the bookmarks.create() method.
19 bookmarks.get() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, get
Given the ID of a bookmarks.BookmarkTreeNode or an array of such IDs, the bookmarks.get() method retrieves the matching nodes.
20 bookmarks.getChildren() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, getChildren
bookmarks.getChildren() retrieves all the immediate children of a given bookmark folder, identified as a bookmarks.BookmarkTreeNode ID.
21 bookmarks.getRecent() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, getRecent
The bookmarks.getRecent() method retrieves a specified number of the most recently added bookmarks as an array of bookmarks.BookmarkTreeNode objects.
22 bookmarks.getSubTree() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, getSubTree
The bookmarks.getSubTree() method asynchronously retrieves a bookmarks.BookmarkTreeNode, given its ID.
23 bookmarks.getTree() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, getTree
bookmarks.getTree() returns an array containing the root of the bookmarks tree as a bookmarks.BookmarkTreeNode object.
24 bookmarks.move() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, move
The bookmarks.move() method moves the specified bookmarks.BookmarkTreeNode to the specified destination within the tree of bookmarks. This lets you move a bookmark to a new folder and/or position within the folder.
25 bookmarks.onChanged API, Add-ons, Bookmarks, Event, Extensions, Non-standard, Reference, WebExtensions, onChanged
Fired when there is a change to:
26 bookmarks.onChildrenReordered API, Add-ons, Bookmarks, Event, Extensions, Non-standard, Reference, WebExtensions, onChildrenReordered
Fired when the children of a folder have changed their order due to the order being sorted in the UI. This is not called as a result of a call to bookmarks.move() or a drag operation in the UI.
27 bookmarks.onCreated API, Add-ons, Bookmarks, Event, Extensions, Non-standard, Reference, WebExtensions, onCreated
Fired when a bookmark item (a bookmark or a folder) is created.
28 bookmarks.onImportBegan API, Add-ons, Bookmarks, Event, Extensions, Non-standard, Reference, WebExtensions, onImportBegan
Fired when the browser has started importing a set of bookmarks.
29 bookmarks.onImportEnded API, Add-ons, Bookmarks, Event, Extensions, Non-standard, Reference, WebExtensions, onImportEnded
Fired when the browser has finished importing a set of bookmarks.
30 bookmarks.onMoved API, Add-ons, Bookmarks, Event, Extensions, Non-standard, Reference, WebExtensions, onMoved
Fired when a bookmark or folder is moved to a different parent folder and/or position within a folder.
31 bookmarks.onRemoved API, Add-ons, Bookmarks, Event, Extensions, Non-standard, Reference, WebExtensions, onRemoved
Fired when a bookmark or folder is removed. When a folder is removed recursively, a single notification is fired for the folder, and none for its contents.
32 bookmarks.remove() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, remove
The bookmarks.remove() method removes a single bookmark or an empty bookmark folder.
33 bookmarks.removeTree() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, WebExtensions, removeTree
The bookmarks.removeTree() method recursively removes a bookmark folder and all of its contents.
34 bookmarks.search() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, Search, WebExtensions
The bookmarks.search() function searches for bookmark tree nodes matching the given query.
35 bookmarks.update() API, Add-ons, Bookmarks, Extensions, Method, Non-standard, Reference, Update, WebExtensions
bookmarks.update() updates the title and/or URL of a bookmark, or the name of a bookmark folder.
36 browserAction API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, browserAction
Adds a button to the browser's toolbar.
37 browserAction.ColorArray API, Add-ons, ColorArray, Extensions, Non-standard, Reference, Type, WebExtensions, browserAction
An array of four integers in the range 0-255, defining an RGBA color. The four values specify the following channels:
38 browserAction.disable() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, disable
Disables the browser action for a tab, meaning that it cannot be clicked when that tab is active.
39 browserAction.enable() API, Add-ons, Enable, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction
Enables the browser action for a tab. By default, browser actions are enabled for all tabs.
40 browserAction.getBadgeBackgroundColor() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, getBadgeBackgroundColor
Gets the background color of the browser action's badge.
41 browserAction.getBadgeText() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, getBadgeText
Gets the browser action's badge text.
42 browserAction.getBadgeTextColor() API, Add-ons, Extensions, Method, Reference, WebExtensions, browserAction, getBadgeTextColor
Gets the text color for the browser action's badge.
43 browserAction.getPopup() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, getPopup
Gets the HTML document set as the popup for this browser action.
44 browserAction.getTitle() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, getTitle
Gets the browser action's title.
45 browserAction.ImageDataType API, Add-ons, Extensions, ImageDataType, Non-standard, Reference, Type, WebExtensions, browserAction
Pixel data for an image. Must be an ImageData object (for example, from a canvas element).
46 browserAction.isEnabled() API, Add-ons, Extensions, Method, Reference, WebExtensions, browserAction, isEnabled
Returns true if the browser action is enabled.
47 browserAction.onClicked API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, browserAction, onClicked
Fired when a browser action icon is clicked. This event will not fire if the browser action has a popup.
48 browserAction.openPopup() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, openPopup
Open the browser action's popup.
49 browserAction.setBadgeBackgroundColor() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, setBadgeBackgroundColor
Sets the background color for the badge. Tabs without a specific badge background color will inherit the global badge background color, which defaults to [217, 0, 0, 255] in Firefox.
50 browserAction.setBadgeText() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, setBadgeText
Sets the badge text for the browser action. The badge is displayed on top of the icon.
51 browserAction.setBadgeTextColor() API, Add-ons, Extensions, Method, Reference, WebExtensions, browserAction, setBadgeTextColor
Sets the text color for the browser action's badge. Tabs without a specific badge text color will inherit the global badge text color.
52 browserAction.setIcon() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, setIcon
Sets the icon for the browser action.
53 browserAction.setPopup() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, browserAction, setPopup
Sets the HTML document that will be opened as a popup when the user clicks on the browser action's icon. Tabs without a specific popup will inherit the global popup, which defaults to the default_popup specified in the manifest.
54 browserAction.setTitle() API, Add-ons, Extensions, Method, Reference, WebExtensions, browserAction, setTitle
Sets the browser action's title. The title is displayed in a tooltip over the browser action's icon. You can pass a tabId in or a windowId as an optional parameter — if you do this then the title is changed only for the given tab or the given window. Tabs or windows without a specific title will inherit the global title text, which defaults to the default_title or name specified in the manifest.
55 browserSettings API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, browserSettings
Enables an extension to modify certain global browser settings. Each property of this API is a types.BrowserSetting object, providing the ability to modify a particular setting.
56 browserSettings.allowPopupsForUserEvents API, Add-ons, Extensions, Property, WebExtensions, allowPopupsForUserEvents, browserSettings
A types.BrowserSetting object that can be used to enable or disable the ability of web pages to open popups in response to user actions.
57 browserSettings.cacheEnabled API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, cacheEnabled
A types.BrowserSetting object that can be used to globally enable or disable the browser cache.
58 browserSettings.closeTabsByDoubleClick API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, closeTabsByDoubleClick
A types.BrowserSetting object that can be used to enable or disable the user's ability to close a tab using double-click.
59 contextMenuShowEvent API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, contextMenuShowEvent
A types.BrowserSetting object which determines whether the browser's context menu is shown on the mouseup event or on the mousedown event.
60 browserSettings.ftpProtocolEnabled API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, contextMenuShowEvent, ftpProtocolEnabled
A types.BrowserSetting object that determines whether the FTP protocol is enabled in the browser.
61 browserSettings.homepageOverride API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, homepageOverride
A types.BrowserSetting object that can be used to get a string representing the URL currently set as the browser's homepage.
62 browserSettings.imageAnimationBehavior API, Add-ons, Extensions, Property, Reference, browserSettings, imageAnimationBehavior
A types.BrowserSetting object that can be used to change the way the browser handles animated images, such as GIFs.
63 browserSettings.newTabPageOverride API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, newTabPageOverride
A types.BrowserSetting object that can be used to get a string representing the URL for the "new tab" page: that is, the page that's loaded when the user opens a new empty tab.
64 browserSettings.newTabPosition API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, newTabPosition
A types.BrowserSetting object that can be used to control the position of newly opened tabs relative to already open tabs.
65 browserSettings.openBookmarksInNewTabs API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, openBookmarksInNewTabs
A types.BrowserSetting object whose underlying value is a boolean.
66 browserSettings.openSearchResultsInNewTabs API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, openSearchResultsInNewTabs
A types.BrowserSetting object whose underlying value is a boolean.
67 browserSettings.openUrlbarResultsInNewTabs API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, openUrlbarResultsInNewTabs
A types.BrowserSetting object whose underlying value is a boolean.
68 browserSettings.overrideDocumentColors API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, overrideDocumentColors
A types.BrowserSetting object whose underlying value is a string.
69 browserSettings.useDocumentFonts API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, useDocumentFonts
A types.BrowserSetting object whose underlying value is a boolean.
70 browserSettings.webNotificationsDisabled API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, webNotificationsDisabled
A types.BrowserSetting object that can be used to prevent websites from showing notifications using the Notifications Web API.
71 browserSettings.zoomFullPage API, Add-ons, Extensions, Property, Reference, WebExtensions, browserSettings, zoomFullPage
A types.BrowserSetting object whose underlying value is a boolean.
72 browserSettings.zoomSiteSpecific API, Add-ons, Extensions, Property, WebExtensions, browserSettings, zoomSiteSpecific
A types.BrowserSetting object whose underlying value is a boolean.
73 browsingData API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, browsingData
Enables extensions to clear the data that is accumulated while the user is browsing.
74 browsingData.DataTypeSet API, Add-ons, DataTypeSet, Extensions, Reference, Type, WebExtensions, browsingData
The browsingData.DataTypeSet type describes a set of data types.
75 browsingData.RemovalOptions API, Add-ons, Extensions, Reference, RemovalOptions, Type, WebExtensions, browsingData
The browsingData.RemovalOptions type contains options to control certain aspects of browsing data removal.
76 browsingData.remove() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, remove
Removes the specified browsing data.
77 browsingData.removeCache() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removeCache
Clears the browser's cache.
78 browsingData.removeCookies() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removeCookies
Clears the browser's cookies.
79 browsingData.removeDownloads() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removeDownloads
Clears the browser's download history. Note that this does not delete the downloaded objects themselves, only records of downloads in the browser's history.
80 browsingData.removeFormData() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removeDownloads
Clears data that the browser has saved for autofilling forms.
81 browsingData.removeHistory() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removeHistory
Clears the record of web pages that the user has visited (browsing history).
82 browsingData.removeLocalStorage() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removeLocalStorage
Clears any local storage created by websites.
83 browsingData.removePasswords() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removePasswords
Clears saved passwords.
84 browsingData.removePluginData() API, Add-ons, Extensions, Method, Reference, WebExtensions, browsingData, removePluginData
Clears data stored by browser plugins.
85 browsingData.settings() API, Add-ons, Extensions, Method, Reference, Settings, WebExtensions, browsingData
Browsers have a built-in "Clear History" feature, which enables the user to clear various types of browsing data. This has a UI that enables the user to select what type of data to remove (e.g. history, downloads, ...) and how far back in time to remove data.
86 captivePortal API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, captivePortal
Determine the captive portal state of the user’s connection. A captive portal is a web page displayed when a user first connects to a Wi-Fi network. The user provides information or acts on the captive portal web page to gain broader access to network resources, such as accepting terms and conditions or making a payment. 
87 captivePortal.canonicalURL API, Add-ons, Extensions, WebExtensions, canonicalURL, captivePortal
Return the canonical URL of the captive-portal detection page. Read-only.
88 getLastChecked API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, captivePortal
Returns the time since the last request was completed.
89 getState API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, captivePortal
Returns the portal state as one of unknown, not_captive, unlocked_portal, or locked_portal.
90 onConnectivityAvailable API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, captivePortal
Fires when the captive portal service determines that the user can connect to the internet. 
91 onStateChanged API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, captivePortal
Fires when the captive portal state changes.
92 clipboard API, Add-ons, Clipboard, Extensions, Reference, WebExtensions
The WebExtension clipboard API (which is different from the standard Clipboard API) enables an extension to copy items to the system clipboard. Currently the WebExtension clipboard API only supports copying images, but it's intended to support copying text and HTML in the future.
93 clipboard.setImageData() API, Add-ons, Clipboard, Extensions, Method, Reference, WebExtensions, setImageData
Copies an image to the clipboard. The image is re-encoded before it is written to the clipboard. If the image is invalid, the clipboard is not modified.
94 commands API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, commands
Listen for the user executing commands that you have registered using the commands manifest.json key.
95 Command API, Add-ons, Command, Extensions, Non-standard, Reference, Type, WebExtensions, commands
Information about a command. This contains the information specified for the command in the commands manifest.json key.
96 getAll() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, commands, getAll
Gets all commands for the extension that you have registered using the commands manifest.json key.
97 onCommand API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, commands, onCommand
The listener is passed the command's name. This matches the name given to the command in its manifest.json entry.
98 commands.reset() API, Add-ons, Extensions, Method, Reference, WebExtensions, commands, reset
Resets the given command's description and keyboard shortcut to the values given in the extension's commands manifest.json key.
99 commands.update() API, Add-ons, Extensions, Method, Reference, Update, WebExtensions, commands
Change the description or keyboard shortcut for the given command.
100 contentScripts API, Add-ons, Extensions, Interface, WebExtensions, contentScripts
With the contentScripts API, an extension can register and unregister scripts at runtime.
101 contentScripts.register() API, Extensions, Method, Reference, contentScripts, register
Use this function to register one or more content scripts.
102 contentScripts.RegisteredContentScript API, Extensions, Reference, RegisteredContentScript, Type, contentScripts
RegisteredContentScript is returned by a call to contentScripts.register() and represents the content scripts registered in that call.
103 contentScripts.RegisteredContentScript.unregister() API, Extensions, Reference, RegisteredContentScript.unregister, contentScripts
Unregisters the content scripts represented by this RegisteredContentScript object.
104 contextualIdentities WebExtensions
Work with contextual identities: list, create, remove, and update contextual identities.
105 contextualIdentities.ContextualIdentity API, Add-ons, ContextualIdentity, Extensions, Reference, Type, WebExtensions, contextualIdentities
The contextualIdentities.ContextualIdentity type describes a single contextual identity.
106 contextualIdentities.create() API, Add-ons, Create, Extensions, Method, Reference, WebExtensions, contextualIdentities
Creates a new contextual identity. Once created, the user will be able to create new tabs belonging to this contextual identity, just as they can with the built-in identities.
107 contextualIdentities.get() API, Add-ons, Extensions, Method, Reference, WebExtensions, contextualIdentities, get
Gets information about a contextual identity, given its cookie store ID.
108 contextualIdentities.onCreated API, APIReference, Add-ons, Event, Extensions, WebExtensions, contextualIdentities, onCreated
Fired when a new contextual identity is created. Contextual identities may be created by extensions using the contextualIdentities API, or directly by the user, using the browser's user interface.
109 contextualIdentities.onRemoved API, Add-ons, Event, Extensions, Reference, WebExtensions, contextualIdentities, onRemoved
Fired when a new contextual identity is removed. Contextual identities may be removed by extensions using the contextualIdentities API, or directly by the user, using the browser's user interface.
110 contextualIdentities.onUpdated API, Add-ons, Event, Extensions, Reference, WebExtensions, contextualIdentities, onUpdated
Fired when the properties of a contextual identity, such as its name, icon, or color, are changed. Contextual identities may be updated by extensions using the contextualIdentities API, or directly by the user, using the browser's user interface.
111 contextualIdentities.query() API, Add-ons, Extensions, Method, Reference, WebExtensions, contextualIdentities, query
Gets information about all contextual identities, or about those contextual identities that match a given filter argument.
112 contextualIdentities.remove() API, Add-ons, Extensions, Method, Reference, WebExtensions, contextualIdentities, remove
Removes a contextual identity, given its cookie store ID.
113 contextualIdentities.update() API, Add-ons, Extensions, Method, Reference, Update, WebExtensions, contextualIdentities
Updates properties of a contextual identity, given its cookie store ID.
114 cookies API, Add-ons, Cookies, Extensions, Interface, Non-standard, Reference, WebExtensions
Enables extensions to get and set cookies, and be notified when they change.
115 cookies.Cookie API, Add-ons, Cookies, Extensions, Non-standard, Reference, Type, WebExtensions, cookie
The Cookie type of the cookies API represents information about an HTTP cookie.
116 cookies.CookieStore API, Add-ons, CookieStore, Cookies, Extensions, Non-standard, Reference, Type, WebExtensions
The CookieStore type of the cookies API represents a cookie store in the browser.
117 cookies.get() API, Add-ons, Cookies, Extensions, Method, Non-standard, Reference, WebExtensions, get
The get() method of the cookies API retrieves information about a single cookie, given its name and URL.
118 cookies.getAll() API, Add-ons, Cookies, Extensions, Method, Non-standard, Reference, WebExtensions, getAll
The getAll() method of the cookies API retrieves all cookies from a single cookie store that match the given information.
119 cookies.getAllCookieStores() API, Add-ons, Cookies, Extensions, Method, Non-standard, Reference, WebExtensions, getAllCookieStores
The getAllCookieStores() method of the cookies API returns a list of all cookie stores.
120 cookies.onChanged API, Add-ons, Cookies, Event, Extensions, Non-standard, Reference, WebExtensions, onChanged
The onChanged event of the cookies API is fired when a cookie is set or removed.
121 cookies.OnChangedCause API, Add-ons, Cookies, Extensions, Non-standard, OnChangedCause, Reference, Type, WebExtensions
The OnChangedCause type of the cookies API represents the reason a cookie changed.
122 cookies.remove() API, Add-ons, Cookies, Extensions, Method, Non-standard, Reference, WebExtensions, remove
The remove() method of the cookies API deletes a cookie, given its name and URL.
123 cookies.SameSiteStatus API, Add-ons, Cookies, Extensions, Interface, Non-standard, Reference, Type, WebExtensions
The SameSiteStatus type of the cookies API represents information about the SameSite state of a cookie.
124 cookies.set() API, Add-ons, Cookies, Extensions, Method, Non-standard, Reference, WebExtensions, set
The set() method of the cookies API sets a cookie containing the specified cookie data. This method is equivalent to issuing an HTTP Set-Cookie header during a request to a given URL.
125 devtools API, Add-ons, Extensions, Reference, WebExtensions, devtools.inspectedWindow, devtools.network, devtools.panels
Enables extensions to interact with the browser's Developer Tools. You can use this API to create Developer Tools pages, interact with the window that is being inspected, inspect the page network usage.
126 devtools.inspectedWindow API, Add-ons, Extensions, Reference, WebExtensions, devtools.inspectedWindow
The devtools.inspectedWindow API lets a devtools extension interact with the window that the developer tools are attached to.
127 devtools.inspectedWindow.eval() API, Add-ons, Extensions, Method, Reference, WebExtensions, devtools.inspectedWindow, eval
Executes JavaScript in the window that the devtools are attached to.
128 devtools.inspectedWindow.reload() API, Add-ons, Extensions, Method, Reference, WebExtensions, devtools.inspectedWindow, reload
Reloads the window that the devtools are attached to.
129 devtools.inspectedWindow.tabId API, Add-ons, Extensions, Property, Reference, WebExtensions, devtools.inspectedWindow, tabId
The ID of the tabs.Tab that this instance of the devtools is attached to, represented as a number.
130 devtools.network API, Add-ons, Extensions, Reference, WebExtensions, devtools.network
The devtools.network API lets a devtools extension get information about network requests associated with the window that the devtools are attached to (the inspected window).
131 devtools.network.getHAR() Add-ons, Extensions, Method, WebExtensions, devtools.network, getHAR
Get a HAR log for the page loaded in the current tab.
132 devtools.network.onNavigated API, Add-ons, Event, Extensions, Reference, WebExtensions, devtools.network
Fired when the user navigates the inspected window to a new page.
133 devtools.network.onRequestFinished API, Add-ons, Event, Extensions, Reference, WebExtensions, devtools.network, onRequestFinished
Fired when a network request has finished and its details are available to the extension.
134 devtools.panels API, Add-ons, Extensions, Reference, WebExtensions, devtools.panels
The devtools.panels API lets a devtools extension define its user interface inside the devtools window.
135 devtools.panels.create() API, Add-ons, Create, Extensions, Method, Reference, WebExtensions, devtools.panels
Adds a new panel to the devtools.
136 devtools.panels.elements API, Add-ons, Elements, Extensions, Property, Reference, WebExtensions, devtools.panels
An ElementsPanel object, which represents the browser's HTML/CSS inspector.
137 devtools.panels.ElementsPanel API, Add-ons, DevTools, Extensions, Reference, Type, WebExtensions, devtools.panels, devtools.panels.ElementsPanel
An ElementsPanel represents the HTML/CSS inspector in the browser's devtools. This is called the Page Inspector in Firefox and the Elements panel in Chrome.
138 devtools.panels.ElementsPanel.createSidebarPane() API, Add-ons, DevTools, Extensions, Method, Reference, WebExtensions, createSidebarPane, devtools.panels
Adds a new pane to the sidebar in the HTML/CSS inspector.
139 onSelectionChanged API, Add-ons, DevTools, Event, Extensions, Reference, WebExtensions, devtools.panels, devtools.panelsElementsPanel
Fires when the user selects a different page element for inspection with the browser's developer tools, for example by selecting the "Inspect Element" context menu item in Firefox.
140 devtools.panels.ExtensionPanel API, Add-ons, Extensions, Reference, Type, WebExtensions, devtools.panels
An ExtensionPanel represents a panel added to the devtools. It's the resolution of the Promise returned by browser.devtools.panels.create().
141 devtools.panels.ExtensionSidebarPane API, Add-ons, DevTools, Extensions, Reference, Type, WebExtensions, devtools.panels, devtools.panels.ExtensionSidebarPane
The ExtensionSidebarPane object represents a pane that an extension has added to the sidebar in the browser's HTML/CSS inspector.
142 devtools.panels.ExtensionSidebarPane.onHidden API, Add-ons, Event, ExtensionSidebarPane, Extensions, Reference, WebExtensions, devtools.panels, onHidden
Called when the sidebar pane becomes hidden, as a result of the user switching away from it.
143 devtools.panels.ExtensionSidebarPane.onShown API, Add-ons, Event, ExtensionSidebarPane, Extensions, Reference, WebExtensions, devtools.panels, onShown
Fired when the sidebar pane becomes visible as a result of the user switching to it.
144 devtools.panels.ElementsPanel.setExpression() API, Add-ons, Extensions, Method, Reference, WebExtensions, devtools.panels, setExpression
Evaluates an expression in the context of the inspected page, and displays the result in the extension sidebar pane.
145 devtools.panels.ExtensionSidebarPane.setObject() API, Add-ons, Extensions, Method, Reference, WebExtensions, devtools.panels, setObject
Displays a JSON object in the extension's sidebar pane.
146 devtools.panels.ExtensionSidebarPane.setPage() API, Add-ons, Extensions, Method, Reference, WebExtensions, setPage
Sets an HTML page to be displayed in the sidebar pane.
147 devtools.panels.onThemeChanged API, Add-ons, DevTools, Event, Reference, WebExtensions, devtools.panels, onThemeChanged
Fired when the devtools theme changes.
148 devtools.panels.themeName API, Add-ons, DevTools, Property, Reference, WebExtensions, devtools.panels, themeName
The name of the currently selected devtools theme.
149 dns API, Add-ons, DNS, Extensions, WebExtensions
Enables an extension to resolve domain names.
150 dns.resolve() API, Add-ons, DNS, Extensions, Method, Reference, WebExtensions, resolve
Resolves the given hostname to a DNS record.
151 downloads API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, downloads
Enables extensions to interact with the browser's download manager. You can use this API module to download files, cancel, pause, resume downloads, and show downloaded files in the file manager.
152 downloads.acceptDanger() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, acceptDanger, downloads
The acceptDanger() function of the downloads API prompts the user to either accept or cancel a potentially dangerous download.
153 downloads.BooleanDelta API, Add-ons, BooleanDelta, Extensions, Non-standard, Reference, Type, WebExtensions, downloads
The BooleanDelta type of the downloads API represents the difference between two booleans.
154 downloads.cancel() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, cancel, downloads
The cancel() function of the downloads API cancels a download. The call will fail if the download is not active: for example, because it has completed downloading.
155 downloads.DangerType API, Add-ons, DangerType, Extensions, Non-standard, Reference, Type, WebExtensions, downloads
The DangerType type of the downloads API defines a set of possible reasons that a downloadable file might be considered dangerous.
156 downloads.DoubleDelta API, Add-ons, DoubleDelta, Extensions, Non-standard, Reference, Type, WebExtensions, downloads
The DoubleDelta type of the downloads API represents the difference between two doubles.
157 downloads.download() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, download, downloads
The download() function of the downloads API downloads a file, given its URL and other optional preferences.
158 downloads.DownloadItem API, Add-ons, DownloadItem, Extensions, Non-standard, Reference, Type, WebExtensions, downloads
The DownloadItem type of the downloads API represents a downloaded file.
159 downloads.DownloadQuery API, Add-ons, DownloadQuery, Extensions, Non-standard, Reference, Type, WebExtensions, downloads
The DownloadQuery type of the downloads API defines a set of parameters that can be used to search the downloads manager for a specific set of downloads.
160 downloads.DownloadTime API, Add-ons, DownloadTime, Extensions, Non-standard, Reference, Type, WebExtensions, downloads
The DownloadTime type of the downloads API represents the time a download took to complete.
161 downloads.drag() API, Add-ons, Drag, Extensions, Method, Non-standard, Reference, WebExtensions, downloads
The drag() function of the downloads API initiates dragging the downloaded file to another application.
162 downloads.erase() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, erase
The erase() function of the downloads API erases matching downloads.DownloadItem from the browser's download history, without deleting the downloaded files from disk.
163 downloads.FilenameConflictAction API, Add-ons, Extensions, FilenameConflictAction, Non-standard, Reference, Type, WebExtensions, downloads
The FilenameConflictAction type of the downloads API specifies what to do if the name of a downloaded file conflicts with an existing file.
164 downloads.getFileIcon() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, getFileIcon
The getFileIcon() function of the downloads API retrieves an icon for the specified download.
165 downloads.InterruptReason API, Add-ons, Extensions, InterruptReason, Non-standard, Reference, Type, WebExtensions, downloads
The InterruptReason type of the downloads API defines a set of possible reasons why a download was interrupted.
166 downloads.onChanged API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, downloads, onChanged
The onChanged() event of the downloads API is fired when any of a downloads.DownloadItem's properties changes (except for bytesReceived).
167 downloads.onCreated API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, downloads, onCreated
The onCreated() event of the downloads API fires when a download begins, i.e. when downloads.download() is successfully invoked.
168 downloads.onErased API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, downloads, onErased
The onErased() event of the downloads API fires when a download is erased from the browser history.
169 downloads.open() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, open
The open() function of the downloads API opens the downloaded file with its associated application. A downloads.onChanged event will fire when the item is opened for the first time.
170 downloads.pause() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, pause
The pause() function of the downloads API pauses a download.
171 downloads.removeFile() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, removeFile
The removeFile() function of the downloads API removes a downloaded file from disk.
172 downloads.resume() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, resume
The resume() function of the downloads API resumes a paused download. If the request was successful, the download will be unpaused and progress will resume. The resume() call will fail if the download is not active: for example, because it has finished downloading.
173 downloads.search() API, Add-ons, Extensions, Method, Non-standard, Reference, Search, WebExtensions, downloads
The search() function of the downloads API queries the downloads.DownloadItem available in the browser's downloads manager, and returns those that match the specified search criteria.
174 downloads.setShelfEnabled() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, setShelfEnabled
The setShelfEnabled() function of the downloads API enables or disables the gray shelf at the bottom of every window associated with the current browser profile. The shelf will be disabled as long as at least one extension has disabled it.
175 downloads.show() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, show
The show() function of the downloads API shows the downloaded file in its containing folder in the underlying platform's file manager.
176 downloads.showDefaultFolder() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, downloads, showDefaultFolder
The showDefaultFolder() function of the downloads API opens the default downloads folder in the platform's file manager.
177 downloads.State API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, downloads, state
The State type of the downloads API defines different states that a current download can be in.
178 downloads.StringDelta API, Add-ons, Extensions, Non-standard, Reference, StringDelta, Type, WebExtensions, downloads
The StringDelta type of the downloads API represents the difference between two strings.
179 events API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, events
Common types used by APIs that dispatch events.
180 events.Event API, Add-ons, Event, Extensions, Non-standard, Reference, Type, WebExtensions, events
An object which allows the addition and removal of listeners for a browser event.
181 events.Rule API, Add-ons, Extensions, Non-standard, Reference, Rule, Type, WebExtensions, events
Description of a declarative rule for handling events.
182 events.UrlFilter API, Add-ons, Extensions, Non-standard, Reference, Type, UrlFilter, WebExtensions, events
Describes various criteria for filtering URLs. If all of the criteria specified in the filter's properties match the URL, then the filter matches. Filters are often provided to API methods in an Array of UrlFilters. For example, webNavigation listeners can be added with a filter which is an object with a single url property that is an Array of UrlFilters, e.g. {url:[UrlFilter,UrlFilter,...]}. If any filter within the Array of UrlFilters matches, then it is considered a match for the Array. Effectively, the criteria specified within a single filter are AND'ed together, while all of the individual filters within an Array are OR'ed.
183 extension API, Add-ons, Extension, Extensions, Interface, Reference, WebExtensions
Utilities related to your extension. Get URLs to resources packages with your extension. Get the Window object for your extension's pages. Get the values for various settings.
184 extension.getBackgroundPage() API, Add-ons, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, getBackgroundPage
Alias for runtime.getBackgroundPage().
185 extension.getExtensionTabs() API, Add-ons, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, getExtensionTabs
This method has been deprecated. Use extension.getViews() instead.
186 extension.getURL() API, Add-ons, Deprecated, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, getURL
This function is deprecated. Please use runtime.getURL.
187 extension.getViews() API, Add-ons, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, getViews
Returns an array of the Window objects for each of the pages running inside the current extension. This includes, for example:
188 extension.inIncognitoContext API, Add-ons, Extension, Extensions, Non-standard, Property, Reference, WebExtensions, inIncognitoContext
Boolean value, true for content scripts running inside private browsing tabs and for extension pages running inside a private browsing process.
189 extension.isAllowedFileSchemeAccess() API, Add-ons, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, isAllowedFileSchemeAccess
This is an asynchronous function that returns a Promise.
190 extension.isAllowedIncognitoAccess() API, Add-ons, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, isAllowedIncognitoAccess
Check whether the extension is allowed access to tabs opened in "private browsing" mode.
191 extension.lastError API, Add-ons, Extension, Extensions, Non-standard, Property, Reference, WebExtensions, lastError
An alias for runtime.lastError.
192 extension.onRequest API, Add-ons, Event, Extension, Extensions, Non-standard, Reference, WebExtensions, onRequest
Not implemented: This is not implemented in Firefox because it has been deprecated since Chrome 33. Please use runtime.onMessage instead.
193 extension.onRequestExternal API, Add-ons, Event, Extension, Extensions, Non-standard, Reference, WebExtensions, onRequestExternal
Not implemented: This is not implemented in Firefox because it has been deprecated since Chrome 33. Please use runtime.onMessageExternal instead.
194 extension.sendRequest() API, Add-ons, Deprecated, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, sendRequest
Sends a single request to other listeners within the extension. Similar to runtime.connect, but only sends a single request with an optional response. The extension.onRequest event is fired in each page of the extension.
195 extension.setUpdateUrlData() API, Add-ons, Extension, Extensions, Method, Non-standard, Reference, WebExtensions, setUpdateUrlData
Sets parameters for the extension's update URL. This value is ignored for extensions that are hosted in the browser vendor's store.
196 extension.ViewType API, Add-ons, Extension, Extensions, Non-standard, Reference, Type, ViewType, WebExtensions
The type of extension view.
197 extensionTypes API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, extensionTypes
Some common types used in other WebExtension APIs.
198 extensionTypes.ImageDetails API, Add-ons, Extensions, ImageDetails, Non-standard, Reference, Type, WebExtensions, extensionTypes
Details about the format, quality, area and scale of a captured image.
199 extensionTypes.ImageFormat API, Add-ons, Extensions, ImageFormat, Non-standard, Reference, Type, WebExtensions, extensionTypes
The format of an image.
200 extensionTypes.InjectDetails API, Add-ons, Extensions, InjectDetails, Non-standard, Reference, Type, WebExtensions, extensionTypes
This type is given as a parameter to the tabs.executeScript(), tabs.insertCSS(), and tabs.removeCSS() methods. For the details of its properties and what they are used for, see the documentation pages for those methods:
201 extensionTypes.RunAt API, Add-ons, Extensions, Non-standard, Reference, RunAt, Type, WebExtensions, extensionTypes
The soonest that the JavaScript or CSS will be injected into the tab.
202 find API, Add-ons, Extensions, Reference, WebExtensions, find
Finds text in a web page, and highlights matches.
203 find.find() API, Add-ons, Extensions, Method, Reference, WebExtensions, find
Searches for text in a tab.
204 find.highlightResults() API, Add-ons, Extensions, Method, Reference, WebExtensions, find, highlightResults
Highlights the results of a previous call to find.find().
205 find.removeHighlighting() API, Add-ons, Extensions, Method, Reference, WebExtensions, find, removeHighlighting
Remove any highlighting of a previous search that was applied by a previous call to find.highlightResults(), or by the browser's native UI.
206 history API, Add-ons, Extensions, History, Interface, Non-standard, Reference, WebExtensions
Use the history API to interact with the browser history.
207 history.addUrl() API, Add-ons, Extensions, History, Method, Non-standard, Reference, WebExtensions, addUrl
Adds a record to the browser's history of a visit to the given URL. The visit's time is recorded as the time of the call, and the history.TransitionType is recorded as "link".
208 history.deleteAll() API, Add-ons, Extensions, History, Method, Non-standard, Reference, WebExtensions, deleteAll
Deletes all visits from the browser's history.
209 history.deleteRange() API, Add-ons, Extensions, History, Method, Non-standard, Reference, WebExtensions, deleteRange
Removes all visits to pages that the user made during the given time range. If this removes all visits made to a given page, then the page will be no longer appear in the browser history and history.onVisitRemoved will fire for it.
210 history.deleteUrl() API, Add-ons, Extensions, History, Method, Non-standard, Reference, WebExtensions, deleteUrl
Removes all visits to the given URL from the browser history.
211 history.getVisits() API, Add-ons, Extensions, History, Method, Non-standard, Reference, WebExtensions, getVisits
Retrieves information about all visits to the given URL.
212 history.HistoryItem API, Add-ons, Extensions, History, HistoryItem, Non-standard, Reference, Type, WebExtensions
A HistoryItem object provides information about a page in the browser history.
213 history.onTitleChanged API, Add-ons, Event, History, Reference, WebExtensions, onTitleChanged
Events have three functions:
214 history.onVisited API, Add-ons, Event, Extensions, History, Non-standard, Reference, WebExtensions, onVisited
Fired each time the user visits a page. A history.HistoryItem object is passed to the listener. This event fires before the page has loaded.
215 history.onVisitRemoved API, Add-ons, Event, Extensions, History, Non-standard, Reference, WebExtensions, onVisitRemoved
Fired when a page is removed completely from the browser history.
216 history.search() API, Add-ons, Extensions, History, Method, Non-standard, Reference, Search, WebExtensions
Searches the browser's history for history.HistoryItem objects matching the given criteria.
217 history.TransitionType API, Add-ons, Extensions, History, Non-standard, Reference, TransitionType, Type, WebExtensions
This describes how the browser navigated to a particular page. For example, "link" means that the browser navigated to the page because the user clicked a link.
218 history.VisitItem API, Add-ons, Extensions, History, Non-standard, Reference, Type, VisitItem, WebExtensions
An object describing a single visit to a page.
219 i18n API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, i18n
Functions to internationalize your extension. You can use these APIs to get localized strings from locale files packaged with your extension, find out the browser's current language, and find out the value of its Accept-Language header.
220 i18n.detectLanguage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, detectLanguage, i18n
Detects the language of the provided text using the Compact Language Detector (CLD).
221 i18n.getAcceptLanguages() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getAcceptLanguages, i18n
Gets the accept-languages of the browser. This is different from the locale used by the browser. To get the locale, use i18n.getUILanguage.
222 i18n.getMessage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getMessage, i18n
Gets the localized string for the specified message.
223 i18n.getUILanguage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getUILanguage, i18n
Gets the UI language of the browser. This is different from i18n.getAcceptLanguages which returns the preferred user languages.
224 i18n.LanguageCode API, Add-ons, Extensions, LanguageCode, Non-standard, Reference, Type, WebExtensions, i18n
A language tag such as "en-US" or "fr".
225 Locale-specific message reference Internationalization, Localization, Reference, String, WebExtensions, i18n, message, messages.json, placeholders
Each internationalized extension has at least one file named messages.json that provides locale-specific strings. This page describes the format of messages.json files.
226 identity API, Add-ons, Extensions, Identity, Reference, WebExtensions
Use the identity API to get an OAuth2 authorization code or access token, which an extension can then use to access user data from a service that supports OAuth2 access (such as Google or Facebook).
227 identity.getRedirectURL() API, Add-ons, Extensions, Identity, Method, Reference, WebExtensions, getRedirectURL
Generates a URL that you can use as a redirect URL.
228 identity.launchWebAuthFlow API, Add-ons, Extensions, Identity, Method, Reference, WebExtensions, launchWebAuthFlow
Performs the first part of an OAuth2 flow, including user authentication and client authorization.
229 idle API, Add-ons, Extensions, Idle, Interface, Non-standard, Reference, WebExtensions
Find out when the user's system is idle, locked, or active.
230 idle.IdleState API, Add-ons, Extensions, Idle, IdleState, Non-standard, Reference, Type, WebExtensions
String describing the device's idle state.
231 idle.onStateChanged API, Add-ons, Event, Extensions, Idle, Non-standard, Reference, WebExtensions, onStateChanged
Fired when the system changes to an active, idle or locked state. The event listener is passed a string that has one of three values:
232 idle.queryState() API, Add-ons, Extensions, Idle, Method, Non-standard, Reference, WebExtensions, queryState
Returns "locked" if the system is locked, "idle" if the user has not generated any input for a specified number of seconds, or "active" otherwise.
233 idle.setDetectionInterval() API, Add-ons, Extensions, Idle, Method, Non-standard, Reference, WebExtensions, setDetectionInterval
Sets the interval, in seconds, used to determine when the system is in an idle state for idle.onStateChanged events. The default interval is 60 seconds.
234 management API, Add-ons, Extensions, Reference, WebExtensions, management
Get information about installed add-ons.
235 ExtensionInfo API, Add-ons, ExtensionInfo, Extensions, Reference, Type, WebExtensions, management
An ExtensionInfo object contains information about an add-on.
236 management.get() API, Add-ons, Method, Reference, WebExtensions, get, management
Retrieves an management.ExtensionInfo object containing information about the specified add-on.
237 management.getAll() API, Add-ons, Method, Reference, WebExtensions, getAll, management
Retrieves an array of management.ExtensionInfo objects, one for each installed add-on.
238 management.getPermissionWarningsById() API, Add-ons, Method, Reference, WebExtensions, getPermissionWarningsById, management
Given the ID of an add-on, this function returns the permission warnings for it as an array of strings.
239 management.getPermissionWarningsByManifest() API, Add-ons, Method, Reference, WebExtensions, getPermissionWarningsByManifest, management
Given the text of a manifest.json file, this function returns the permission warnings that would be given for the resulting add-on, as an array of strings.
240 management.getSelf() API, Add-ons, Method, Reference, WebExtensions, getSelf, management
Retrieves an management.ExtensionInfo object containing information about the calling add-on.
241 management.install() API, Add-ons, Method, Reference, Theme, WebExtensions, install, management
This API requires the "management" API permission and will only work with signed themes.
242 management.onDisabled() API, Add-ons, Event, Reference, WebExtensions, management, onDisabled
Fired when an add-on is disabled.
243 management.onEnabled() API, Add-ons, Event, Reference, WebExtensions, management, onEnabled
The event listener called when the enabled event is fired, indicating that an add-on is now enabled.
244 management.onInstalled() API, Add-ons, Event, Reference, WebExtensions, management, onInstalled
Fired when an add-on is installed.
245 management.onUninstalled() API, Add-ons, Event, Reference, WebExtensions, management, onUninstalled
Fired when an add-on is uninstalled.
246 management.setEnabled() API, Add-ons, Method, Reference, WebExtensions, management, setEnabled
Enables or disables the given add-on.
247 management.uninstall() API, Add-ons, Method, Reference, WebExtensions, management, uninstall
Uninstalls an add-on, given its ID.
248 management.uninstallSelf() API, Add-ons, Method, Reference, WebExtensions, management, uninstallSelf
Uninstalls the calling add-on.
249 menus API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, contextMenus, menus
Add items to the browser's menu system.
250 menus.ACTION_MENU_TOP_LEVEL_LIMIT ACTION_MENU_TOP_LEVEL_LIMIT, API, Add-ons, Extensions, Non-standard, Property, Reference, WebExtensions, contextMenus
The maximum number of top level extension items that can be added to a menu item whose contextMenus.ContextType is "browser_action" or "page_action". Any items beyond this limit will be ignored.
251 menus.ContextType API, Add-ons, ContextType, Extensions, Non-standard, Reference, Type, WebExtensions, contextMenus, menus
The different contexts a menu item can appear in.
252 menus.create() API, Add-ons, Create, Extensions, Method, Non-standard, Reference, WebExtensions, contextMenus
Creates a new menu item, given an options object defining properties for the item.
253 createProperties API, Add-ons, Extensions, WebExtensions, contextMenus, createProperties
An object passed to the  menus.create() or  menus.update() methods to describe the properties of the new or updated menu item.
254 menus.getTargetElement() API, Method, Reference, WebExtensions, getTargetElement, menus
Returns the element for a given targetElementId
255 menus.ItemType API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, contextMenus, itemtype
The type of menu item.
256 menus.OnClickData API, Add-ons, Extensions, Non-standard, OnClickData, Reference, Type, WebExtensions, contextMenus
Information passed to the menus.onClicked event listener when a menu item is clicked.
257 menus.onClicked API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, contextMenus, onClicked
Fired when a menu item is clicked.
258 menus.onHidden API, Add-ons, Event, Extensions, Reference, WebExtensions, menus, onHidden
Fired when the browser stops displaying a menu: for example because the user clicked outside it or selected an item.
259 menus.onShown API, Add-ons, Event, Extensions, Reference, WebExtensions, menus, onShown
Fired when the browser has shown a menu.
260 menus.overrideContext() API, Add-ons, Create, Extensions, Method, WebExtensions, contextMenus
Hide all default Firefox menu items in favor of providing a custom context menu UI.
261 menus.refresh() API, Add-ons, Extensions, Method, Reference, WebExtensions, menus, refresh
Refreshes a menu that's being shown.
262 menus.remove() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, contextMenus, remove
Removes a menu item.
263 menus.removeAll() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, contextMenus, menus, removeAll
Removes all menu items added by the extension.
264 menus.update() API, Add-ons, Extensions, Method, Non-standard, Reference, Update, WebExtensions, contextMenus
Updates a previously created menu item.
265 notifications API, Add-ons, Extensions, Notifications, WebExtensions
Display notifications to the user, using the underlying operating system's notification mechanism. Because this API uses the operating system's notification mechanism, the details of how notifications appear and behave may differ according to the operating system and the user's settings.
266 notifications.clear() API, Add-ons, Extensions, Method, Non-standard, Notifications, Reference, WebExtensions, clear
Clears a notification, given its ID.
267 notifications.create() API, Add-ons, Create, Extensions, Method, Non-standard, Notifications, Reference, WebExtensions
Creates and displays a notification.
268 notifications.getAll() API, Add-ons, Extensions, Method, Non-standard, Notifications, Reference, WebExtensions, getAll
Gets all currently active notifications created by the extension.
269 notifications.NotificationOptions API, Add-ons, Extensions, Non-standard, NotificationOptions, Notifications, Reference, Type, WebExtensions
This type contains all the data needed to:
270 notifications.onButtonClicked API, Add-ons, Event, Extensions, Non-standard, Notifications, Reference, WebExtensions, onButtonClicked
Fired when the user clicks one of the notification's buttons.
271 notifications.onClicked API, Add-ons, Event, Extensions, Non-standard, Notifications, Reference, WebExtensions, onClicked
Fired when the user clicks a notification, but not on any of the notification's buttons (for that, see notifications.onButtonClicked).
272 notifications.onClosed API, Add-ons, Event, Extensions, Non-standard, Notifications, Reference, WebExtensions, onClosed
Fired when a notification is closed, either by the system or by the user.
273 notifications.onShown API, Add-ons, Event, Extensions, Notifications, Reference, WebExtensions, events, onShown
Fired immediately after a notification has been shown.
274 notifications.TemplateType API, Add-ons, Extensions, Non-standard, Notifications, Reference, TemplateType, Type, WebExtensions
This is a string, and represents the type of notification to create. There are four types of notification: "basic", "image", "list", "progress".
275 notifications.update() API, Add-ons, Extensions, Method, Non-standard, Notifications, Reference, Update, WebExtensions
Updates a notification, given its ID.
276 omnibox API, Add-ons, Extensions, Reference, WebExtensions, omnibox
Enables extensions to implement customised behavior when the user types into the browser's address bar.
277 omnibox.onInputCancelled API, Add-ons, Event, Extensions, Reference, WebExtensions, omnibox, onInputCancelled
Fired when the user has cancelled their interaction with your extension (for example, by clicking outside the address bar).
278 omnibox.onInputChanged API, Add-ons, Event, Extensions, Reference, WebExtensions, omnibox, onInputChanged
Fired whenever the user changes their input, after they have started interacting with your extension by entering its keyword in the address bar and then pressing the space key.
279 omnibox.onInputEntered API, Add-ons, Event, Extensions, Reference, WebExtensions, omnibox, onInputEntered
Fired when the user has selected one of the suggestions your extension has added to the address bar's drop-down list.
280 omnibox.OnInputEnteredDisposition API, Add-ons, Extensions, OnInputEnteredDisposition, Reference, Type, WebExtensions, omnibox
The omnibox.OnInputEnteredDisposition type describes how the extension should handle a user selection from the suggestions in the address bar's drop-down list.
281 omnibox.onInputStarted API, Add-ons, Event, Extensions, Reference, WebExtensions, omnibox, onInputStarted
Fired when the user starts interacting with your extension by entering its keyword in the address bar and then pressing the space key.
282 omnibox.setDefaultSuggestion() API, Add-ons, Extensions, Method, Reference, WebExtensions, omnibox, setDefaultSuggestion
Set the default suggestion to appear in the address bar drop-down list when the user starts interacting with your extension.
283 omnibox.SuggestResult API, Add-ons, Extensions, Reference, SuggestResult, Type, WebExtensions, omnibox
The omnibox.SuggestResult type defines a single suggestion that the extension can add to the address bar's drop-down list.
284 pageAction API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, pageAction
A page action is a clickable icon inside the browser's address bar.
285 pageAction.getPopup() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getPopup, pageAction
Gets the URL for the HTML document set as the popup for this page action.
286 pageAction.getTitle() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getTitle, pageAction
Gets the title of the page action.
287 pageAction.hide() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, hide, pageAction
Hides the page action for a given tab.
288 pageAction.ImageDataType API, Add-ons, Extensions, ImageDataType, Non-standard, Reference, Type, WebExtensions, pageAction
Pixel data for an image.
289 pageAction.isShown() API, Add-ons, Extensions, Method, Reference, WebExtensions, isShown, pageAction
Returns true if the page action is being shown for the given tab.
290 pageAction.onClicked API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onClicked, pageAction
Fired when a page action icon is clicked. This event will not fire if the page action has a popup.
291 pageAction.openPopup() API, Add-ons, Extensions, Method, Reference, WebExtensions, close, sidebarAction
You can only call this function from inside the handler for a user action.
292 pageAction.setIcon() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, pageAction, setIcon
Sets the icon for the page action.
293 pageAction.setPopup() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, pageAction, setPopup
Sets the HTML document to be opened as a popup when the user clicks on the page action's icon.
294 pageAction.setTitle() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, pageAction, setTitle
Sets the title of the page action. The title is displayed in a tooltip when the user hovers over the page action.
295 pageAction.show() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, pageAction, show
Shows the pageAction for a given tabs/Tab. The page action is shown whenever the given tab is the active tab.
296 permissions API, Add-ons, Extensions, Permissions, Reference, WebExtensions
Extensions need permissions to access more powerful WebExtension APIs. They can ask for permissions at install time, by including the permissions they need in the permissions manifest.json key. The main advantages of asking for permissions at install time are:
297 permissions.contains() API, Add-ons, Contains, Method, Permissions, Reference, WebExtensions
Check whether the extension has the permissions listed in the given permissions.Permissions object.
298 permissions.getAll() API, Add-ons, Method, Permissions, Reference, WebExtensions, getAll
Retrieve a permissions.Permissions object containing all the permissions currently granted to the extension.
299 permissions.onAdded API, Add-ons, Event, Permissions, Reference, WebExtensions, onAdded
Fired when the extension granted new permissions.
300 permissions.onRemoved API, Add-ons, Event, Permissions, Reference, WebExtensions, onRemoved
Fired when some permissions are removed from the extension.
301 Permissions API, Add-ons, Permissions, Reference, Type, WebExtensions
A Permissions object represents a collection of permissions.
302 permissions.remove() API, Add-ons, Method, Permissions, Reference, WebExtensions, remove
Ask to give up the permissions listed in the given permissions.Permissions object.
303 permissions.request() API, Add-ons, Method, Permissions, Reference, WebExtensions, request
Ask for the set of permissions listed in the given permissions.Permissions object.
304 pkcs11 API, API Extensions, Add-ons, Extensions, Reference, Web, Web Development, WebExtensions, pkcs11
The pkcs11 API enables an extension to enumerate PKCS #11 security modules and to make them accessible to the browser as sources of keys and certificates.
305 pkcs11.getModuleSlots() API, Add-ons, Extensions, Method, Reference, WebExtensions, getModuleSlots, pkcs11
Enumerate a module's slots. This function returns an array containing one entry for each slot. Each entry contains the slot's name and, if the slot contains a token, information about the token.
306 pkcs11.installModule() API, Add-ons, Extensions, Method, Reference, WebExtensions, installModule, pkcs11
Installs the named PKCS #11 module, making it available to Firefox.
307 pkcs11.isModuleInstalled() API, Add-ons, Extensions, Method, Reference, WebExtensions, isModuleInstalled, pkcs11
Checks whether the named PKCS #11 module is currently installed in Firefox.
308 pkcs11.uninstallModule() API, Add-ons, Extensions, Method, Reference, WebExtensions, pkcs11, uninstallModule
Uninstalls the named PKCS #11 module from Firefox.
309 privacy API, Add-ons, Extensions, Privacy, Reference, WebExtensions
Access and modify various privacy-related browser settings.
310 privacy.network API, Add-ons, Extensions, Network, Privacy, Property, Reference, WebExtensions
The privacy.network property contains privacy-related network settings. Each property is a types.BrowserSetting object.
311 privacy.services API, Add-ons, Extensions, Privacy, Property, Reference, Services
The privacy.services property contains privacy-related settings controlling services offered by the browser or by third parties. Each property is a types.BrowserSetting object.
312 privacy.websites API, Add-ons, Extensions, Privacy, Property, Reference, WebExtensions, websites
The privacy.websites property contains privacy-related settings controlling the way to browser interacts with websites. Each property is a types.BrowserSetting object.
313 proxy API, Add-ons, Proxy, WebExtensions
Use the proxy API to proxy web requests. You can use the proxy.onRequest event listener to intercept web requests, and return an object that describes whether and how to proxy them.
314 proxy.onError API, Add-ons, Event, Proxy, Reference, WebExtensions, onProxyError
Fired when there is an error evaluating the PAC file or the onRequest listener.
315 proxy.onRequest API, Add-ons, Event, Extensions, Proxy, Reference, WebExtensions, onRequest
Fired when a web request is about to be made, to give the extension an opportunity to proxy it.
316 proxy.ProxyInfo Add-ons, Extensions, Proxy, ProxyInfo, Type, WebExtensions
Contains information about a proxy. This object, or an array of these objects, is returned from the listener to proxy.onRequest. It instructs the browser whether to proxy the request, and if so, which proxy to use.
317 proxy.register() API, Add-ons, Function, Method, Proxy, Reference, WebExtensions, register, registerProxyScript
Registers a Proxy Auto-Configuration (PAC) file. The file is executed immediately, and its FindProxyForURL() function will be called for any HTTP or HTTPS requests.
318 proxy.RequestDetails Add-ons, Extensions, Proxy, RequestDetails, Type, WebExtensions
Contains information about a web request. An instance of this object is passed into the proxy.onRequest listener.
319 proxy.settings API, Add-ons, Extensions, Property, Proxy, Reference, Settings, WebExtensions
A types.BrowserSetting object that can be used to change the browser's proxy settings.
320 proxy.unregister() API, Add-ons, Extensions, Method, Proxy, Reference, WebExtensions, unregister
Unregisters a Proxy Auto-Configuration (PAC) file. that was registered by an earlier call to proxy.register().
321 runtime API, Add-ons, Extensions, Interface, Reference, WebExtensions, runtime
This module provides information about your extension and the environment it's running in.
322 runtime.connect() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, connect, runtime
Make a connection between different contexts inside the extension.
323 runtime.connectNative() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, connectNative, runtime
For more information, see Native messaging.
324 runtime.getBackgroundPage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getBackgroundPage, runtime
Retrieves the Window object for the background page running inside the current extension.
325 runtime.getBrowserInfo() API, Add-ons, Extensions, Method, Reference, WebExtensions, getBrowserInfo, runtime
Returns information about the browser in which the extension is installed.
326 runtime.getManifest() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getManifest, runtime
Get the complete manifest.json file, deserialized from JSON to an object.
327 runtime.getPackageDirectoryEntry() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getPackageDirectoryEntry, runtime
Returns a DirectoryEntry object representing the package directory.
328 runtime.getPlatformInfo() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getPlatformInfo, runtime
Returns information about the current platform. This can only be called in the background script context.
329 runtime.getURL() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getURL, runtime
Given a relative path from the manifest.json to a resource packaged with the extension, return a fully-qualified URL.
330 runtime.id API, Add-ons, Extensions, Non-standard, Property, Reference, WebExtensions, id, runtime
The ID of the extension.
331 runtime.lastError API, Add-ons, Extensions, Non-standard, Property, Reference, WebExtensions, lastError, runtime
This value is used to report an error message from an asynchronous API, when the asynchronous API is given a callback. This is useful for extensions that are using the callback-based version of the WebExtension APIs.
332 runtime.MessageSender API, Add-ons, Extensions, MessageSender, Non-standard, Reference, Type, WebExtensions, runtime
An object containing information about the sender of a message or connection request; this is passed to the runtime.onMessage() listener.
333 runtime.onBrowserUpdateAvailable API, Add-ons, Deprecated, Event, Extensions, Non-standard, Reference, WebExtensions, onBrowserUpdateAvailable, runtime
Fired when an update for the browser is available, but it isn't installed immediately because a browser restart is required.
334 runtime.onConnect API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onconnect, runtime
Fired when a connection is made with either an extension process or a content script.
335 runtime.onConnectExternal API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onConnectExternal, runtime
Fired when an extension receives a connection request from a different extension.
336 runtime.onInstalled API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onInstalled, runtime
Fired when the extension is first installed, when the extension is updated to a new version, and when the browser is updated to a new version.
337 runtime.OnInstalledReason API, Add-ons, Extensions, Non-standard, OnInstalledReason, Reference, Type, WebExtensions, runtime
The reason that the runtime.onInstalled event is being dispatched.
338 runtime.onMessage API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onmessage, runtime
Use this event to listen for messages from another part of your extension.
339 runtime.onMessageExternal API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onMessageExternal, runtime
Use this event to listen for messages from another extension.
340 runtime.onRestartRequired API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onRestartRequired, runtime
Fired when an app or the device that it runs on needs to be restarted. The app should close all its windows at its earliest convenience to let the restart happen. If the app does nothing, a restart will be enforced after a 24-hour grace period has passed. Currently, this event is only fired for Chrome OS kiosk apps.
341 runtime.OnRestartRequiredReason API, Add-ons, Extensions, Non-standard, OnRestartRequiredReason, Reference, Type, WebExtensions, runtime
The reason that the runtime.onRestartRequired event is being dispatched.
342 runtime.onStartup API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onStartup, runtime
Fired when a profile that has this extension installed first starts up. This event is not fired when a private browsing/incognito profile is started, even if this extension is operating in 'split' incognito mode.
343 runtime.onSuspend API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onSuspend, runtime
Sent to the event page just before it is unloaded. This gives the extension an opportunity to do some cleanup. Note that since the page is unloading, any asynchronous operations started while handling this event are not guaranteed to complete.
344 runtime.onSuspendCanceled API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onSuspendCanceled, runtime
Sent after runtime.onSuspend to indicate that the app won't be unloaded after all.
345 runtime.onUpdateAvailable API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onUpdateAvailable, runtime
Fired when an update to the extension is available. This event enables an extension to delay an update: for example, because it is in the middle of some operation which should not be interrupted.
346 runtime.openOptionsPage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, openOptionsPage, runtime
This is an asynchronous function that returns a Promise.
347 runtime.PlatformArch API, Add-ons, Extensions, Non-standard, PlatformArch, Reference, Type, WebExtensions, runtime
The machine's processor architecture.
348 runtime.PlatformInfo API, Add-ons, Extensions, Non-standard, PlatformInfo, Reference, Type, WebExtensions, runtime
An object containing information about the current platform.
349 runtime.PlatformNaclArch API, Add-ons, Extensions, Non-standard, PlatformNaclArch, Reference, Type, WebExtensions, runtime
The native client architecture. This may be different from arch on some platforms.
350 runtime.PlatformOs API, Add-ons, Extensions, Non-standard, PlatformOs, Reference, Type, WebExtensions, runtime
The operating system the browser is running on.
351 runtime.Port API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, port, runtime
A Port object represents one end of a connection between two specific contexts, which can be used to exchange messages.
352 runtime.reload() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, reload, runtime
Reloads the extension.
353 runtime.requestUpdateCheck() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, requestUpdateCheck, runtime
Checks to see if an update for the extension is available.
354 runtime.RequestUpdateCheckStatus API, Add-ons, Extensions, Non-standard, Reference, RequestUpdateCheckStatus, Type, WebExtensions, runtime
Result of a call to runtime.requestUpdateCheck().
355 runtime.sendMessage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, runtime, sendMessage
Sends a single message to event listeners within your extension or a different extension.
356 runtime.sendNativeMessage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, runtime, sendNativeMessage
Sends a single message from an extension to a native application.
357 runtime.setUninstallURL() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, runtime, setUninstallURL
Sets the URL to be visited when the extension is uninstalled. This may be used to clean up server-side data, do analytics, or implement surveys. The URL can be a maximum 255 characters.
358 search API, Add-ons, Extensions, Reference, Search, Search Engines, WebExtensions
Retrieves search engines and executes a search with a specific search engine.
359 search.get() API, Add-ons, Extensions, Method, Reference, Search, WebExtensions, get
Gets an array of all installed search engines.
360 search.search() API, Add-ons, Extensions, Reference, Search, Search Engines, WebExtensions
Perform a search using the search engine specified, or the default search engine if no search engine is specified.
361 sessions API, Add-ons, Extensions, Non-standard, Reference, WebExtensions, sessions
Use the sessions API to list, and restore, tabs and windows that have been closed while the browser has been running.
362 sessions.Filter API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, filter, sessions
The Filter object enables you to restrict the number of sessions.Session objects returned by a call to sessions.getRecentlyClosed().
363 sessions.forgetClosedTab() API, Add-ons, Extensions, Method, Reference, WebExtensions, forgetClosedTab, sessions
This is an asynchronous function that returns a Promise.
364 sessions.forgetClosedWindow() API, Add-ons, Extensions, Method, Reference, WebExtensions, forgetClosedWindow, sessions
This is an asynchronous function that returns a Promise.
365 sessions.getRecentlyClosed() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getRecentlyClosed, sessions
Returns an array of sessions.Session objects, representing windows and tabs that were closed in the current browsing session (that is: the time since the browser was started).
366 sessions.getTabValue() API, Add-ons, Extensions, Method, Reference, WebExtensions, getTabValue, sessions
Retrieves a value previously stored by a call to sessions.setTabValue.
367 sessions.getWindowValue() API, Add-ons, Extensions, Method, Reference, WebExtensions, getWindowValue, sessions
Retrieves a value previously stored by a call to sessions.setWindowValue.
368 sessions.MAX_SESSION_RESULTS API, Add-ons, Extensions, MAX_SESSION_RESULTS, Non-standard, Property, Reference, WebExtensions, sessions
This value represents the maximum number of sessions that will be returned by a call to sessions.getRecentlyClosed(). It is read-only for WebExtension code, and is set to 25.
369 sessions.onChanged API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onChanged, sessions
Fired whenever the list of closed tabs or windows changes.
370 sessions.removeTabValue() API, Add-ons, Extensions, Method, Reference, WebExtensions, removeTabValue, sessions
Removes a value previously stored by a call to sessions.setTabValue.
371 sessions.removeWindowValue() API, Add-ons, Extensions, Method, Reference, WebExtensions, removeWindowValue, sessions
Removes a value previously stored by a call to sessions.setWindowValue.
372 sessions.restore() API, Add-ons, Extensions, Method, Non-standard, WebExtensions, restore, sessions
Restores a closed tab or window. Restoring doesn't just reopen the tab or window: it also restores the tab's navigation history so the back/forward buttons will work. Restoring a window will restore all the tabs that the window contained when it was closed.
373 sessions.Session API, Add-ons, Extensions, Non-standard, Reference, Session, Type, WebExtensions, sessions
The Session object represents a tab or window that the user has closed in the current browsing session.
374 sessions.setTabValue() API, Add-ons, Extensions, Method, Reference, WebExtensions, sessions, setTabValue
Stores a key/value pair to associate with a given tab. You can subsequently retrieve this value using sessions.getTabValue.
375 sessions.setWindowValue() API, Add-ons, Extensions, Method, Reference, WebExtensions, sessions, setWindowValue
Stores a key/value pair to associate with a given window. You can subsequently retrieve this value using sessions.getWindowValue.
376 sidebarAction API, Extensions, Non-standard, Reference, Sidebar, WebExtensions, sidebarAction
Gets and sets properties of an extension's sidebar.
377 sidebarAction.close() API, Add-ons, Extensions, Method, Reference, WebExtensions, close, sidebarAction
Closes the sidebar in the active window, if it is the extension's own sidebar.
378 sidebarAction.getPanel() API, Add-ons, Extensions, Method, Reference, WebExtensions, getPanel, sidebarAction
Gets a URL to the HTML document that defines the sidebar's contents.
379 sidebarAction.getTitle() API, Add-ons, Extensions, Method, Reference, WebExtensions, getTitle, sidebarAction
Gets the sidebar's title.
380 sidebarAction.ImageDataType API, Add-ons, Extensions, ImageDataType, Reference, Type, WebExtensions, sidebarAction
Pixel data for an image. Must be an ImageData object (for example, from a canvas element).
381 sidebarAction.isOpen() API, Add-ons, Extensions, Method, Reference, WebExtensions, isOpen, sidebarAction
Returns true if the extension's sidebar is open in a given window.
382 sidebarAction.open() API, Add-ons, Extensions, Method, Reference, open, sidebarAction
You can only call this function from inside the handler for a user action.
383 sidebarAction.setIcon() API, Add-ons, Extensions, Method, Reference, WebExtensions, setIcon, sidebarAction
Sets the icon for the sidebar.
384 sidebarAction.setPanel() API, Add-ons, Extensions, Method, Reference, WebExtensions, setPanel, sidebarAction
Sets the sidebar's panel: that is, the HTML document that defines the content of this sidebar.
385 sidebarAction.setTitle() API, Add-ons, Extensions, Method, Reference, WebExtensions, setTitle, sidebarAction
Sets the sidebar's title. The title is displayed anywhere the browser lists available sidebars. For example, Firefox will show it in the "View > Sidebar" menu. It's also shown at the top o the sidebar when the sidebar is open.
386 sidebarAction.toggle() API, Add-ons, Extensions, Method, Reference, WebExtensions, sidebarAction, toggle
Toggles the visibility of the sidebar in the active window, if the sidebar belongs to the extension.
387 storage API, Add-ons, Extensions, Interface, Non-standard, Reference, Storage, WebExtensions
Enables extensions to store and retrieve data, and listen for changes to stored items.
388 storage.local API, Add-ons, Extensions, Non-standard, Property, Reference, Storage, WebExtensions, local
Represents the local storage area. Items in local storage are local to the machine the extension was installed on.
389 storage.managed API, Add-ons, Extensions, Non-standard, Property, Reference, Storage, WebExtensions, managed
A storage.StorageArea object that represents the managed storage area. Items in managed storage are set by the domain administrator or other native applications installed on user's computer, and are read-only for the extension. Trying to modify this storage area results in an error.
390 storage.onChanged API, Add-ons, Event, Extensions, Non-standard, Reference, Storage, WebExtensions, onChanged
Fired when one or more items change.
391 storage.StorageArea API, Add-ons, Extensions, Non-standard, Reference, Storage, StorageArea, Type, WebExtensions
StorageArea is an object representing a storage area.
392 StorageArea.clear() API, Add-ons, Extensions, Method, Non-standard, Reference, Storage, StorageArea, WebExtensions, remove
Removes all items from the storage area.
393 StorageArea.get() API, Add-ons, Extensions, JavaScript, Method, Non-standard, Reference, Storage, StorageArea, Web, WebExtensions, get
Retrieves one or more items from the storage area.
394 StorageArea.getBytesInUse() API, Add-ons, Extensions, Method, Non-standard, Reference, Storage, StorageArea, WebExtensions, getBytesInUse
Gets the amount of storage space, in bytes, used one or more items being stored in the storage area.
395 StorageArea.remove() API, Add-ons, Extensions, Method, Non-standard, Reference, Storage, StorageArea, WebExtensions, remove
Removes one or more items from the storage area.
396 StorageArea.set() API, Add-ons, Extensions, Method, Non-standard, Reference, Storage, StorageArea, WebExtensions, set
Stores one or more items in the storage area, or update existing items.
397 storage.StorageChange API, Add-ons, Extensions, Non-standard, Reference, Storage, StorageChange, Type, WebExtensions
StorageChange objects contain the following properties:
398 storage.sync API, Add-ons, Extensions, Non-standard, Property, Reference, Storage, Sync, WebExtensions
Represents the sync storage area. Items in sync storage are synced by the browser, and are available across all instances of that browser that the user is logged into (e.g. via Firefox sync, or a Google account), across different devices.
399 tabs API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, tabs
Interact with the browser's tab system.
400 tabs.captureTab() API, Add-ons, Extensions, Method, Reference, WebExtensions, captureTab, tabs
Creates a data URI encoding the image of an area of the given tab. You must have the <all_urls> permission to use this method.
401 tabs.captureVisibleTab() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, captureVisibleTab, tabs
Creates a data URI encoding the image of an area of the currently active tab in the specified window. You must have the <all_urls> permission to use this method. (Alternately, Chrome allows use of this method with the activeTab permission and a qualifying user gesture).
402 tabs.connect() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, connect, tabs
Call this function to set up a connection between the extension's background scripts (or other privileged scripts, such as popup scripts or options page scripts) and any content scripts that belong to this extension and are running in the specified tab. This function returns a runtime.Port object.
403 tabs.create() API, Add-ons, Create, Extensions, Method, Non-standard, Reference, WebExtensions, tabs
Creates a new tab.
404 tabs.detectLanguage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, detectLanguage, tabs
Detects the primary language of the content in a tab, using the Compact Language Detector (CLD).
405 tabs.discard() API, Add-ons, Extensions, Method, WebExtensions, discard, tabs
Discards one or more tabs.
406 tabs.duplicate() API, Add-ons, Duplicate, Extensions, Method, Non-standard, Reference, WebExtensions, tabs
Duplicates a tab, given its ID.
407 tabs.executeScript() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, executeScript, tabs
Injects JavaScript code into a page.
408 tabs.get() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, get, tabs
Given a tab ID, get the tab's details as a tabs.Tab object.
409 tabs.getAllInWindow() API, Add-ons, Deprecated, Extensions, Method, Non-standard, Reference, WebExtensions, getAllInWindow, tabs
Gets details about all tabs in the specified window.
410 tabs.getCurrent() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getCurrent, tabs
Get a tabs.Tab containing information about the tab that this script is running in.
411 tabs.getSelected() API, Add-ons, Deprecated, Extensions, Method, Non-standard, Reference, WebExtensions, getSelected, tabs
This method has been deprecated. Use tabs.query instead.
412 tabs.getZoom() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getZoom, tabs
Gets the current zoom factor for the specified tab.
413 tabs.getZoomSettings() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getZoomSettings, tabs
Gets the current zoom settings for a specified tab.
414 tabs.goBack() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, goBack
Navigate to the previous page in tab's history, if available.
415 tabs.goForward() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, goForward
Navigate to the next page in tab's history, if available.
416 tabs.hide() API, Add-ons, Extensions, Method, Reference, WebExtensions, hide, tabs
Hides one or more tabs.
417 tabs.highlight() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, highlight, tabs
This is an asynchronous function that returns a Promise.
418 tabs.insertCSS() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, insertCSS, tabs
Injects CSS into a page.
419 tabs.move() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, move, tabs
Moves one or more tabs to a new position in the same window or to a different window.
420 tabs.moveInSuccession() API, Add-ons, Extensions, Method, Reference, WebExtensions, tabs
Modifies the succession relationship for a group of tabs.
421 tabs.MutedInfo API, Add-ons, Extensions, MutedInfo, Non-standard, Reference, Type, WebExtensions, tabs
This object contains a boolean indicating whether the tab is muted, and the reason for the last state change.
422 tabs.MutedInfoReason API, Add-ons, Extensions, MutedInfoReason, Non-standard, Reference, Type, WebExtensions, tabs
Specifies the reason a tab was muted or unmuted.
423 tabs.onActivated API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onActivated, tabs
Fires when the active tab in a window changes. Note that the tab's URL may not be set at the time this event fired, but you can listen to tabs.onUpdated events to be notified when a URL is set.
424 tabs.onActiveChanged API, Add-ons, Deprecated, Event, Extensions, Non-standard, Reference, WebExtensions, onActiveChanged, tabs
This event is deprecated. Use tabs.onActivated instead.
425 tabs.onAttached API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onAttached, tabs
Fired when a tab is attached to a window, for example because it was moved between windows.
426 tabs.onCreated API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onCreated, tabs
Fired when a tab is created.
427 tabs.onDetached API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onDetached, tabs
Fired when a tab is detached from a window, for example because it is being moved between windows.
428 tabs.onHighlightChanged API, Add-ons, Deprecated, Event, Extensions, Non-standard, Reference, WebExtensions, onHighlightChanged, tabs
Fired when the highlighted or selected tabs in a window changes.
429 tabs.onHighlighted API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onHighlighted, tabs
Fired when the set of highlighted tabs in a window changes.
430 tabs.onMoved API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onMoved, tabs
Fired when a tab is moved within a window.
431 tabs.onRemoved API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onRemoved, tabs
Fired when a tab is closed.
432 tabs.onReplaced API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onReplaced, tabs
Fired when a tab is replaced with another tab due to prerendering or instant.
433 tabs.onSelectionChanged API, Add-ons, Deprecated, Event, Extensions, Non-standard, Reference, WebExtensions, onSelectionChanged, tabs
Fires when the selected tab in a window changes.
434 tabs.onUpdated API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onUpdated, tabs
Fired when a tab is updated.
435 tabs.onZoomChange API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onZoomChange, tabs
Fired when a tab is zoomed.
436 tabs.PageSettings API, Add-ons, Extensions, PageSettings, Reference, Type, WebExtensions, tabs
The type tabs.PageSettings is used to control how a tab is rendered as a PDF by the tabs.saveAsPDF() method.
437 tabs.print() API, Add-ons, Extensions, Method, Reference, WebExtensions, print, tabs
Call this function to print the contents of the active tab. If this function is called, the user will be presented with the print dialog from the underlying platform, and will have the chance to change the print settings and then print the currently active tab.
438 tabs.printPreview() API, Add-ons, Extensions, Method, Reference, WebExtensions, printPreview, tabs
Opens print preview for the active tab.
439 tabs.query() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, query, tabs
Gets all tabs that have the specified properties, or all tabs if no properties are specified.
440 tabs.reload() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, reload, tabs
Reload a tab, optionally bypassing the local web cache.
441 tabs.remove() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, remove, tabs
Closes one or more tabs.
442 tabs.removeCSS() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, removeCSS, tabs
Removes from a page CSS which was previously injected by a call to tabs.insertCSS().
443 tabs.saveAsPDF() API, Add-ons, Extensions, Method, Reference, WebExtensions, saveAsPDF, tabs
Saves the current page as a PDF file. This will open a dialog, supplied by the underlying operating system, asking the user where they want to save the PDF file.
444 tabs.sendMessage() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, sendMessage, tabs
Sends a single message from the extension's background scripts (or other privileged scripts, such as popup scripts or options page scripts) to any content scripts or extension pages/iframes that belong to the extension and are running in the specified tab.
445 tabs.sendRequest() API, Add-ons, Deprecated, Extensions, Method, Non-standard, Reference, WebExtensions, sendRequest, tabs
This method has been deprecated. Use tabs.sendMessage() instead.
446 tabs.setZoom() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, setZoom, tabs
Zooms the specified tab.
447 tabs.setZoomSettings() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, setZoomSettings, tabs
Sets zoom settings for the specified tab. These settings are reset to the default settings upon navigating the tab.
448 tabs.show() API, Add-ons, Extensions, Method, Reference, WebExtensions, show, tabs
Shows one or more tabs that were previously hidden by a call to tabs.hide.
449 tabs.TAB_ID_NONE API, Add-ons, Extensions, Non-standard, Property, Reference, TAB_ID_NONE, WebExtensions, tabs
A special ID value given to tabs that are not browser tabs (for example, tabs in devtools windows).
450 tabs.Tab API, Add-ons, Extensions, Non-standard, Reference, Tab, Type, WebExtensions, tabs
The type tabs.Tab contains information about a tab. This provides access to information about what content is in the tab, how large the content is, what special states or restrictions are in effect, and so forth.
451 tabs.TabStatus API, Add-ons, Extensions, Non-standard, Reference, TabStatus, Type, WebExtensions, tabs
Indicates whether the tab has finished loading.
452 tabs.toggleReaderMode() API, Add-ons, Extensions, Method, Reference, WebExtensions, tabs, toggleReaderMode
Toggles Reader Mode for the given tab.
453 tabs.update() API, Add-ons, Extensions, Method, Non-standard, Reference, Update, WebExtensions, tabs
Navigate the tab to a new URL, or modify other properties of the tab.
454 tabs.warmup() API, Add-ons, Extensions, Method, Reference, WebExtensions, tabs, warmup
To optimize system resource usage, browsers may drop GPU resources associated with tabs that the user has not accessed for a certain amount of time. If a browser has done this for a tab, then reactivating the tab (for example, when the user switches to it) may take longer than it normally would.
455 tabs.WindowType API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, WindowType, tabs
The type of window that hosts this tab.
456 tabs.ZoomSettings API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, ZoomSettings, tabs
Defines zoom settings for a tab: tabs.ZoomSettingsModetabs.ZoomSettingsScope, and default zoom factor.
457 tabs.ZoomSettingsMode API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, ZoomSettingsMode, tabs
Defines how zoom changes are handled. Extensions can pass this value into tabs.setZoomSettings() to control how the browser handles attempts to change zoom settings for a tab. Defaults to "automatic".
458 tabs.ZoomSettingsScope API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, ZoomSettingsScope, tabs
Defines whether zoom changes will persist for the page's origin, or only take effect in this tab. This defaults to per-origin when tabs.zoomSettingsMode is "automatic", and is always per-tab otherwise.
459 theme Extensions, Themes, WebExtensions, add-on
Enables browser extensions to update the browser theme.
460 theme.getCurrent() API, Add-ons, Extensions, Method, Reference, Theme, WebExtensions, getCurrent
Gets the currently used theme as a theme.Theme object. The arguments available in the color object are listed in the properties of the color.
461 theme.onUpdated Add-ons, Event, Extensions, Theme, WebExtensions
Fires when a theme supplied as a browser extension is applied or removed. Specifically:
462 theme.reset() API, Add-ons, Extensions, Method, Reference, Theme, WebExtensions, reset
Resets any theme that was applied using the theme.update() method.
463 Theme Extension, Theme, Type, WebExtensions, add-on
A Theme object represents the specification of a theme.
464 theme.update() API, Add-ons, Extensions, Method, Reference, Theme, Update, WebExtensions
Updates the browser theme according to the content of given theme.Theme object.
465 topSites API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, topSites
Use the topSites API to get an array containing pages that the user has visited frequently.
466 topSites.get() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, get, topSites
Gets an array containing information about pages that the user has visited often and recently. 
467 topSites.MostVisitedURL API, Add-ons, Extensions, MostVisitedURL, Non-standard, Reference, Type, WebExtensions, topSites
The MostVisitedURL type contains two properties: the title of a page and its URL.
468 types API, Add-ons, Extensions, Reference, Types, WebExtensions
Defines the BrowserSetting type, which is used to represent a browser setting.
469 BrowserSetting API, Add-ons, BrowserSetting, Extensions, Reference, Type, Types, WebExtensions
A BrowserSetting is an object representing a browser setting.
470 clear() API, Add-ons, Extensions, Method, Reference, Types, WebExtensions, clear
Use BrowserSetting.clear() to clear any changes the extension has made to the browser setting. The browser setting will revert to its previous value.
471 get() API, Add-ons, Extensions, Method, Reference, Types, WebExtensions, get
The BrowserSetting.get() method gets the current value of the browser setting, and an enumeration indicating how the setting's value is currently controlled.
472 BrowserSetting.onChange API, Add-ons, BrowserSetting, Event, Extensions, Privacy, Reference, WebExtensions, onchange
The BrowserSetting.onChange event is fired when the setting is changed.
473 set() API, Add-ons, BrowserSetting, Extensions, Privacy, Reference, WebExtensions, set
Use BrowserSetting.set() to change the browser setting to a new value.
474 userScripts Add-ons, Customization, Extensions, Firefox, Mozilla, Reference, WebExtensions, userScripts
Use this API to register user scripts, third-party scripts designed to manipulate webpages or provide new features. Registering a user script instructs the browser to attach the script to pages that match the URL patterns specified during registration.
475 userScripts.onBeforeScript Add-ons, Addons, Customization, Event, Extensions, Firefox, Mozilla, Reference, User Scripts API, WebExtensions, userScripts
Events have three functions:
476 userScripts.register() Add-ons, Extensions, Method, User Scripts API, WebExtensions, register, userScripts
This method enables user scripts to be registered from an extension's pages (such as the background page).
477 userScripts.RegisteredUserScript API, Extensions, Reference, RegisteredUserScript, Type, userScripts
A RegisteredUserScript object is returned by a call to userScripts.register and represents the user scripts registered in that call.
478 RegisteredUserScript.unregister() Add-ons, Extensions, Method, User Scripts API, WebExtensions, unregister, userScripts
The unregister() method of the userScripts.RegisteredUserScript object unregisters the user scripts represented by the object, user scripts that were registered using  userScripts.register.
479 UserScripts.UserScriptOptions Add-ons, Extensions, Firefox, Guide, Intermediate, NeedsExample, UserScriptOptions, WebExtensions, userScripts
The UserScriptOptions object represents the content scripts to register. It has similar syntax to the contentScript options supported by browser.contentScripts.register. The differences are:
480 Working with userScripts API, Extensions, How-to, Tutorial, userScripts
By implementing userScripts, extension developers can modify how sites look and/or work to better meet user needs.
481 webNavigation API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, webNavigation
Add event listeners for the various stages of a navigation. A navigation consists of a frame in the browser transitioning from one URL to another, usually (but not always) in response to a user action like clicking a link or entering a URL in the location bar.
482 webNavigation.getAllFrames() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getAllFrames, webNavigation
Given a tab ID, retrieves information about all the frames it contains.
483 webNavigation.getFrame() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, getFrame, webNavigation
Retrieves information about a particular frame. A frame may be the top-level frame in a tab or a nested iframe, and is uniquely identified by a tab ID and a frame ID.
484 webNavigation.onBeforeNavigate API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onBeforeNavigate, webNavigation
Fired when the browser is about to start a navigation event.
485 webNavigation.onCommitted API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onCommitted, webNavigation
Fired when a navigation is committed. At least part of the new document has been received from the server and the browser has decided to switch to the new document.
486 webNavigation.onCompleted API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onCompleted, webNavigation
Fired when a document, including the resources it refers to, is completely loaded and initialized. This is equivalent to the DOM load event.
487 webNavigation.onCreatedNavigationTarget API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onCreatedNavigationTarget, webNavigation
Fired when a new window, or a new tab in an existing window, is created to host the target of a navigation. For example, this event is sent when:
488 webNavigation.onDOMContentLoaded API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onDOMContentLoaded, webNavigation
Fired when the DOMContentLoaded event is fired in the page. At this point the document is loaded and parsed, and the DOM is fully constructed, but linked resources such as images, stylesheets and subframes may not yet be loaded.
489 webNavigation.onErrorOccurred API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onErrorOccurred, webNavigation
Fired when an error occurs and the navigation is aborted. This can happen if either a network error occurred, or the user aborted the navigation.
490 webNavigation.onHistoryStateUpdated API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onHistoryStateUpdated, webNavigation
Fired when the page used the >history API to update the URL displayed in the browser's location bar. All future events for this frame will use the updated URL.
491 webNavigation.onReferenceFragmentUpdated API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onReferenceFragmentUpdated, webNavigation
Events have three functions:
492 webNavigation.onTabReplaced API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onTabReplaced, webNavigation
Fired when the contents of the tab is replaced by a different (usually previously pre-rendered) tab.
493 webNavigation.TransitionQualifier API, Add-ons, Extensions, Non-standard, Reference, TransitionQualifier, Type, WebExtensions, webNavigation
Values of this type are strings. Possible values are:
494 webNavigation.TransitionType API, Add-ons, Extensions, Non-standard, Reference, TransitionType, Type, WebExtensions, webNavigation
Cause of the navigation: for example, the user clicked a link, or typed an address, or clicked a bookmark.
495 webRequest API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, webRequest
Add event listeners for the various stages of making an HTTP request, which includes websocket requests on ws:// and wss://. The event listener receives detailed information about the request and can modify or cancel the request.
496 webRequest.BlockingResponse API, Add-ons, BlockingResponse, Extensions, Non-standard, Reference, Type, WebExtensions, webRequest
An object of this type is returned by event listeners that have set "blocking" in their extraInfoSpec argument.
497 webRequest.CertificateInfo API, Add-ons, CertificateInfo, Extensions, Reference, Type, WebExtensions, webRequest
An object describing a single X.509 certificate.
498 webRequest.filterResponseData() API, Add-ons, Extensions, Method, Reference, WebExtensions, filterResponseData, webRequest
Use this function to create a webRequest.StreamFilter object for a request. Then use the stream filter to monitor and modify the response. You'd typically call this function from a webRequest event listener.
499 webRequest.getSecurityInfo() API, Add-ons, Extensions, Method, Reference, WebExtensions, getSecurityInfo, webRequest
Use this function to get detailed information about the TLS connection associated with a particular request.
500 webRequest.handlerBehaviorChanged() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, handlerBehaviorChanged, webRequest
Suppose an extension's job is to block web requests against a pattern, and the following scenario happens:
501 webRequest.HttpHeaders API, Add-ons, Extensions, HttpHeaders, Non-standard, Reference, Type, WebExtensions, webRequest
An array of HTTP headers. Each header is represented as an object with two properties: name and either value or binaryValue.
502 webRequest.MAX_HANDLER_BEHAVIOR_CHANGED_CALLS_PER_10_MINUTES API, Add-ons, Extensions, MAX_HANDLER_BEHAVIOR_CHANGED_CALLS_PER_10_MINUTES, Non-standard, Property, Reference, WebExtensions, webRequest
The maximum number of times that webRequest.handlerBehaviorChanged can be called in a 10 minute period.
503 webRequest.onAuthRequired API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onAuthRequired, webRequest
Fired when the server sends a 401 or 407 status code (that is, when the server is asking the client to provide authentication credentials, such as a username and password).
504 webRequest.onBeforeRedirect API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onBeforeRedirect, webRequest
Fired when a server-initiated redirect is about to occur.
505 webRequest.onBeforeRequest API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onBeforeRequest, webRequest
This event is triggered when a request is about to be made, and before headers are available. This is a good place to listen if you want to cancel or redirect the request.
506 webRequest.onBeforeSendHeaders API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onBeforeSendHeaders, webRequest
This event is triggered before sending any HTTP data, but after all HTTP headers are available. This is a good place to listen if you want to modify HTTP request headers.
507 webRequest.onCompleted API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onCompleted, webRequest
Fired when a request has completed.
508 webRequest.onErrorOccurred API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onErrorOccurred, webRequest
Fired when a request could not be processed due to an error: for example, a lack of Internet connectivity.
509 webRequest.onHeadersReceived API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onHeadersReceived, webRequest
Fired when the HTTP response headers for a request are received. Use this event to modify HTTP response headers.
510 webRequest.onResponseStarted API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onResponseStarted, webRequest
Fired when the first byte of the response body is received.
511 webRequest.onSendHeaders API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, onSendHeaders, webRequest
This event is fired just before sending headers. If your extension or some other extension modified headers in webRequest.onBeforeSendHeaders, you'll see the modified version here.
512 webRequest.RequestFilter API, Add-ons, Extensions, Non-standard, Reference, RequestFilter, Type, WebExtensions, webRequest
An object describing filters to apply to webRequest events.
513 webRequest.ResourceType API, Add-ons, Extensions, Non-standard, Reference, ResourceType, Type, WebExtensions, webRequest
This type is a string, which represents the context in which a resource was fetched in a web request.
514 webRequest.SecurityInfo API, Add-ons, Reference, SecurityInfo, Type, WebExtensions, webRequest
An object describing the security properties of a particular web request. An object of this type is returned from the webRequest.getSecurityInfo() API.
515 webRequest.StreamFilter API, Add-ons, Extensions, Reference, StreamFilter, Type, WebExtensions, webRequest
A StreamFilter is an object you can use to monitor and modify HTTP responses.
516 webRequest.StreamFilter.close() Add-ons, Extensions, Method, StreamFilter.close, WebExtensions, webRequest
Closes the request. After this is called, no further response data will be passed to the browser's rendering engine and no more filter events will be given to the extension.
517 webRequest.StreamFilter.disconnect() API, Add-ons, Extensions, StreamFilter.disconnect, WebExtensions, webRequest
You should always call disconnect() or close() once you don't need to interact with the response any further.
518 webRequest.Streamfilter.error API, Add-ons, Extensions, Reference, StreamFilter.error, WebExtensions, webRequest
A string that will contain an error message after the webRequest.StreamFilter.onerror event has fired.
519 webRequest.StreamFilter.ondata API, Add-ons, Extensions, Reference, StreamFilter.ondata, TextDecoder, TextEncoder, WebExtensions, webRequest
An event handler that will be called repeatedly when response data is available. The handler is passed an event object which contains a data property, which contains a chunk of the response data as an ArrayBuffer.
520 webRequest.StreamFilter.onerror API, Add-ons, Extensions, Reference, StreamFilter.onerror, WebExtensions, webRequest
An event handler that will be called when an error occurs. This is most often because an invalid request ID was passed into webRequest.filterResponseData().
521 webRequest.StreamFilter.onstart API, Add-ons, Extensions, Reference, StreamFilter.onstart, WebExtensions, webRequest
An event handler that will be called when the stream is opened and is about to begin delivering data.
522 webRequest.StreamFilter.onstop API, Add-ons, Extensions, Reference, StreamFilter.onstop, WebExtensions, webRequest
An event handler that will be called when the stream has no more data to deliver.
523 webRequest.StreamFilter.resume() API, Add-ons, Extensions, Reference, StreamFilter.resume(), WebExtensions, webRequest
Resumes a request that was previously suspended through a call to webRequest.StreamFilter.suspend().
524 webRequest.StreamFilter.status API, Add-ons, Extensions, Reference, StreamFilter.status, WebExtensions, webRequest
A string that describes the current status of the request.
525 webRequest.StreamFilter.suspend() API, Add-ons, Extensions, Reference, StreamFilter.suspend(), WebExtensions, webRequest
Suspends a request. After this is called, no more data will be delivered until the request is resumed with a call to webRequest.StreamFilter.resume().
526 webRequest.StreamFilter.write() API, Add-ons, Extensions, Reference, StreamFilter.write(), WebExtensions, webRequest
Writes some response data to the output stream.
527 webRequest.UploadData API, Add-ons, Extensions, Non-standard, Reference, Type, UploadData, WebExtensions, webRequest
Contains data uploaded in a URL request.
528 windows API, Add-ons, Extensions, Interface, Non-standard, Reference, WebExtensions, Windows
Interact with browser windows. You can use this API to get information about open windows and to open, modify, and close windows. You can also listen for window open, close, and activate events.
529 windows.create() API, Add-ons, Create, Extensions, Method, Non-standard, Reference, WebExtensions, Windows
Creates a new window.
530 windows.CreateType API, Add-ons, CreateType, Extensions, Non-standard, Reference, Type, WebExtensions, Windows
Specifies the type of browser window to create.
531 windows.get() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, Windows, get
Gets details about a window, given its ID. The details are passed into a callback.
532 windows.getAll() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, Windows, getAll
Gets information about all open windows, passing them into a callback.
533 windows.getCurrent() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, Windows, getCurrent
Gets the current browser window, passing its details into a callback.
534 windows.getLastFocused() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, Windows, getLastFocused
Gets the window that was most recently focused — typically the window 'on top'.
535 windows.onCreated API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, Windows, onCreated
Fired when a window is created.
536 windows.onFocusChanged API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, Windows, onFocusChanged
Fired when the currently focused window changes. Will be windows.WINDOW_ID_NONE if all browser windows have lost focus.
537 windows.onRemoved API, Add-ons, Event, Extensions, Non-standard, Reference, WebExtensions, Windows, onRemoved
Fired when a window is closed.
538 windows.remove() API, Add-ons, Extensions, Method, Non-standard, Reference, WebExtensions, Windows, close, remove
Closes a window and all the tabs inside it, given the window's ID.
539 windows.update() API, Add-ons, Extensions, Method, Non-standard, Reference, Update, WebExtensions, Windows
Updates the properties of a window. Use this to move, resize, and (un)focus a window, etc.
540 windows.WINDOW_ID_CURRENT API, Add-ons, Extensions, Non-standard, Property, Reference, WINDOW_ID_CURRENT, WebExtensions, Windows
browser.windows.WINDOW_ID_CURRENT is a value that can be used as a windowId parameter in some APIs to represent the current window.
541 windows.WINDOW_ID_NONE API, Add-ons, Extensions, Non-standard, Property, Reference, WINDOW_ID_NONE, WebExtensions, Windows
The windowId value that represents the absence of a browser window.
542 windows.Window API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, Window, Windows
Information about a browser window.
543 windows.WindowState API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, WindowState, Windows
The state of this browser window.
544 windows.WindowType API, Add-ons, Extensions, Non-standard, Reference, Type, WebExtensions, WindowType, Windows
The type of browser window this is.
545 Browser actions WebExtensions
A browser action is a button you can add to the browser toolbar. Users can click the button to interact with your extension.
546 Browser compatibility for manifest.json Add-ons, WebExtensions, manifest.json
No summary!
547 Browser support for JavaScript APIs Reference, WebExtensions
No summary!
548 Building a cross-browser extension Add-ons, Extensions, Guide, WebExtensions
The introduction of the browser extensions API created a uniform landscape for the development of browser extensions. However, among the browsers that use the extensions API (the major ones being Chrome, Firefox, Opera, and Edge), there are differences in both the implementation of the API and the scope of coverage. And then, Safari uses its own proprietary Safari Extensions JS.
549 Chrome incompatibilities Guide, WebExtensions, google chrome
Extensions built with WebExtension APIs are designed to be compatible with Chrome and Opera extensions. As far as possible, extensions written for those browsers should run on Firefox with minimal changes.
550 Content scripts WebExtensions
A content script is a part of your extension that runs in the context of a particular web page (as opposed to background scripts which are part of the extension, or scripts which are part of the web site itself, such as those loaded using the script element).
551 Content Security Policy WebExtensions

Extensions developed with WebExtension APIs have a Content Security Policy (CSP) applied to them by default. This restricts the sources from which they can load <script> and <object> resources, and disallows potentially unsafe practices such as the use of eval().

This article explains briefly what a CSP is, what the default policy is and what it means for an extension, and how an extension can change the default CSP.

552 Debugging (before Firefox 50) Debugging, Deprecated, Firefox, Guide, Mozilla, WebExtensions
This article explains how you can use the built-in Firefox developer tools to debug extensions developed with WebExtension APIs. If you're trying to debug an add-on developed with the Add-on SDK, please see the guide to the Add-on Debugger.
553 Developing WebExtensions for Thunderbird Add-ons, Draft, NeedsContent, WebExtensions, thunderbird
You'll approach the coding of an extension for Thunderbird in the same way as you would for a Firefox extension; using a text editor or tool of your choice to write the code.
554 Differences between API implementations Guide, WebExtensions
The browser extensions API is still an emerging standard. As a result, while it is supported by most major browsers including Firefox, Chrome, Edge, and Opera, there are differences between the various implementations. This means that some changes may be necessary to implement your extension for multiple browsers.
555 Example extensions Interface, WebExtensions
To illustrate how to use the WebExtension APIs, we maintain a repository of example extensions at https://github.com/mdn/webextensions-examples. This article describes how to run these examples and lists the examples along with the WebExtension APIs they demonstrate.
556 Extending the developer tools Add-ons, DevTools, Extensions, Guide, Needs Privileges, WebExtensions
You can use WebExtensions APIs to extend the browser's built-in developer tools.
557 Firefox differentiators Add-ons, Draft, Extensions, Firefox, NeedsMarkupWork, Themes, WebExtensions
Firefox is a great place to begin your browser extension development. To start, you get the highest compliance with the proposed browser extension API including use of the browser.* namespace and promises for handling asynchronous events. Then, there is a highly supportive community of extension developers, ready to assist you.
558 Firefox workflow overview Add-ons, Code, Extensions, Firefox, WebExtensions, enhance, prepare, publish, retire, workflow
* Or distribute your extension for sideloading, desktop apps, or in an enterprise.
559 Implement a settings page Guide, JavaScript, Web, WebExtensions
A settings page gives users a way to see and change settings (sometimes also called "preferences" or "options") for the extension.
560 Interact with the clipboard Add-ons, Clip, Clipboard, Cut, Editing, Extensions, Text, WebExtensions, copy, paste
There are two ways browser extensions can interact with the system clipboard: the Document.execCommand() method and the modern asynchronous Clipboard API.
561 Intercept HTTP requests Add-ons, Extensions, How-to, WebExtensions
To intercept HTTP requests, use the webRequest API. This API enables you to add listeners for various stages of making an HTTP request. In the listeners, you can:
562 Internationalization Article, Guide, Internationalization, Localization, WebExtensions, i18n, messages.json, placeholders, predefined messages
The WebExtensions API has a rather handy module available for internationalizing extensions — i18n. In this article we'll explore its features and provide a practical example of how it works. The i18n system for extensions built using WebExtension APIs is similar to common JavaScript libraries for i18n such as i18n.js.
563 manifest.json Add-ons, Extensions, Overview, WebExtensions, manifest.json
The manifest.json file is the only file that every extension using WebExtension APIs must contain.
564 author Add-ons, Extensions, WebExtensions
The extension's author, intended for display in the browser's user interface. If the developer key is supplied and it contains the "name" property, it will override the author key. There's no way to specify multiple authors.
565 background Add-ons, Extensions, Manifest, Reference, WebExtensions
Use the background key to include one or more background scripts, and optionally a background page in your extension.
566 browser_action Add-ons, Extensions, WebExtensions
A browser action is a button that your extension adds to the browser's toolbar. The button has an icon, and may optionally have a popup whose content is specified using HTML, CSS, and JavaScript.
567 browser_specific_settings Add-ons, WebExtensions, browser_specific_settings, manifest.json
The browser_specific_settings key contains keys that are specific to a particular host application.
568 chrome_settings_overrides Add-ons, Extensions, WebExtensions, chrome_settings_overrides, manifest.json
Use the chrome_settings_overrides key to override certain browser settings. Two settings are available:
569 chrome_url_overrides Add-ons, Extensions, WebExtensions
Use the chrome_url_overrides key to provide a custom replacement for the documents loaded into various special pages usually provided by the browser itself.
570 commands Add-ons, Extensions, Keyboard Shortcuts, WebExtensions
Use the commands key to define one or more keyboard shortcuts for your extension.
571 content_scripts Add-ons, Extensions, WebExtensions
Instructs the browser to load content scripts into web pages whose URL matches a given pattern.
572 content_security_policy Add-ons, Extensions, WebExtensions
Extensions have a content security policy applied to them by default. The default policy restricts the sources from which they can load <script> and <object> resources, and disallows potentially unsafe practices such as the use of eval(). See Default content security policy to learn more about the implications of this.
573 default_locale Add-ons, Extensions, WebExtensions
This key must be present if the extension contains the _locales directory, and must be absent otherwise. It identifies a subdirectory of _locales, and this subdirectory will be used to find the default strings for your extension.
574 description Add-ons, Extensions, WebExtensions
A short description of the extension, intended for display in the browser's user interface.
575 developer Add-ons, Extensions, WebExtensions
The name of the extension's developer and their homepage URL, intended for display in the browser's user interface.
576 devtools_page Add-ons, DevTools, Extensions, Manifest, Reference, WebExtensions, devtools_page
Use this key to enable your extension to extend the browser's built-in devtools.
577 dictionaries Add-ons, Extensions, WebExtensions, manifest.json
The dictionaries key specifies the locale_code for which your extension supplies a dictionary. Although the dictionary consists of two files, one with a .dic and one with an .aff file extension, only the one with the .dic extension is referenced in the manifest.json.
578 externally_connectable Add-ons, WebExtensions, manifest.json
Externally connectable allows extension developer to control which other extensions and web pages can communicate with this extension via runtime.connect and runtime.sendMessage message passing. If externally_connectable is not specified, all extensions can communicate with each other but not with web pages.
579 homepage_url Add-ons, Extensions, WebExtensions
URL for the extension's home page.
580 icons Add-ons, Extensions, WebExtensions
The icons key specifies icons for your extension. Those icons will be used to represent the extension in components such as the Add-ons Manager.
581 incognito Add-ons, WebExtensions, incognito, manifest.json
Use the incognito key to control how the extension works with private browsing windows.
582 manifest_version Add-ons, Extensions, WebExtensions
This key specifies the version of manifest.json used by this extension.
583 name Add-ons, Extensions, WebExtensions
Name of the extension. This is used to identify the extension in the browser's user interface and on sites like addons.mozilla.org.
584 offline_enabled Add-ons, Deprecated, Extensions, Non-standard, Offline, WebExtensions, google chrome
Whether the app or extension is expected to work offline. When Chrome detects that it is offline, apps with this field set to true will be highlighted on the New Tab page.
585 omnibox Add-ons, Extensions, WebExtensions
Use the omnibox key to define an omnibox keyword for your extension.
586 optional_permissions Add-ons, WebExtensions, manifest.json, optional_permissions
Use the optional_permissions key to list permissions that you want to ask for at runtime, after your extension has been installed.
587 options_page Add-ons, Deprecated, Extensions, Manifest, Options, WebExtensions, options_page
Use the options_page key to define an options page for your extension.
588 options_ui Add-ons, Extensions, Manifest, Options, Reference, Web, WebExtensions, options_ui
Use the options_ui key to define an options page for your extension.
589 page_action Add-ons, Extensions, WebExtensions
A page action is an icon that your extension adds inside the browser's URL bar.
590 permissions Add-ons, Extensions, Permissions, Reference, WebExtensions, manifest.json
Use the permissions key to request special powers for your extension. This key is an array of strings, and each string is a request for a permission.
591 protocol_handlers Add-ons, Extensions, WebExtensions, manifest.json
Use this key to register one or more web-based protocol handlers.
592 short_name Add-ons, Extensions, WebExtensions
Short name for the extension. If given, this will be used in contexts where the name field is too long. It's recommended that the short name should not exceed 12 characters. If the short name field is not included in manifest.json, then name will be used instead and may be truncated. 
593 sidebar_action WebExtensions
A sidebar is a pane that is displayed at the left-hand side of the browser window, next to the web page. The browser provides a UI that enables the user to see the currently available sidebars and to select a sidebar to display.
594 storage Add-ons, Extensions, Manifest, Reference, WebExtensions
Use the storage key to specify the name of the schema file that defines the structure of data in managed storage.
595 theme_experiment Add-ons, Browser, Customization, Customize, Design, Look and Feel, Themes, colors, theme manifest
This key enables the definition of experimental theme key properties for the Firefox interface. These experiments are a precursor to proposing new theme features for inclusion in Firefox. Experimentation is done by:
596 theme Add-ons, Browser, Customization, Customize, Design, Look and Feel, Themes, colors, theme manifest
Use the theme key to define a static theme to apply to Firefox.
597 user_scripts Add-ons, Extensions, WebExtensions, manifest.json, user_scripts key
Instructs the browser to load a script packaged in the extension, known as the API script, this script is used to export a set of custom API methods for use in user scripts. The API script path, relative to the manifest.json file, is defined as a string in "api_script".
598 version_name Add-ons, Extensions, WebExtensions
In addition to the version field, which is used for update purposes, version_name can be set to a descriptive version string and will be used for display purposes if present.
599 version Add-ons, Extensions, WebExtensions
Version of the extension, formatted as numbers and ASCII characters separated by dots. For the details of the version format, see the Version format page. 
600 Version Format Add-ons, Extensions, WebExtensions
A version string consists of one or more version parts, separated with dots.
601 web_accessible_resources Add-ons, Extensions, WebExtensions
Sometimes you want to package resources—for example, images, HTML, CSS, or JavaScript—with your extension and make them available to web pages.
602 Match patterns in extension manifests WebExtensions
Match patterns are a way to specify groups of URLs: a match pattern matches a specific set of URLs. They are used in WebExtensions APIs in a few places, most notably to specify which documents to load content scripts into, and to specify which URLs to add webRequest listeners to.
603 Modify a web page WebExtensions
One of the most common use cases for an extension is to modify a web page. For example, an extension might want to change the style applied to a page, hide particular DOM nodes, or inject extra DOM nodes into the page.
604 Native manifests Extensions, WebExtensions
Native manifests are specially formatted JSON files that are provisioned on the user's computer by some means outside the extension installation process. For example, a native manifest might be provisioned by a device administrator or by a native application installer.
605 Native messaging WebExtensions
Native messaging enables an extension to exchange messages with a native application, installed on the user's computer. The native messaging serves the extensions without additional accesses over the web.
606 Prerequisites Draft, WebExtensions
All you need is Firefox 45 or higher. See Your first extension to get started.
607 Safely inserting external content into a page Add-ons, Beginner, Extensions, How-to, Security, WebExtensions
There are times when you might want or need to include content from an external source in your extension. But, there is the risk that the source may have malicious scripts embedded in it—added by either the developer of the source or by a malicious third-party.
608 Sharing objects with page scripts Add-ons, Content script, Extensions, Firefox, Guide, Mozilla, Non-standard, WebExtensions, XPCOM, page scripts
As the content scripts guide notes, content scripts don't see changes made to the DOM by scripts loaded by web pages. This means that, for example, if a web page loads a library like jQuery, content scripts won't be able to use it, and have to load their own copy. Conversely, scripts loaded by web pages can't see changes made by content scripts.
609 Tips and Tricks ECMAScript, Tips, Tips and Tricks, WebExtensions, tricks
This page contains various tips and tricks which should be useful to many people developing extensions using WebExtension APIs.
610 User actions Add-ons, Guide, WebExtensions
Some WebExtension APIs perform functions that are generally performed as a result of a user action. For example:
611 User interface Landing, User Interface, WebExtensions
Extensions that use WebExtension APIs are provided with several user interface options so that their functionality can be made available to the user. A summary of those options is provided below, with a more detailed introduction to each user interface option in this section.
612 Toolbar button WebExtension
Commonly referred to as a browser action, this user interface option is a button added to the browser toolbar. Users click the button to interact with your extension.
613 Browser styles Add-ons, Browser style, Example, Extensions, Guide, WebExtensions
Certain user interface components - browser and page action popups, sidebars, and options pages - are specified by your extension in essentially the same way:
614 Context menu items WebExtensions
This user interface option adds one or more items to a browser context menu.
615 devtools panels Beginner, Guide, User Interface, WebExtensions
When an extension provides tools that are of use to developers, it's possible to add a UI for them to the browser's developer tools as a new panel.
616 Extension pages Beginner, User Interface, WebExtensions
You can include HTML pages in your extension to provide forms, help, or any other content your extension needs.
617 Notifications WebExtensions
Notifications allow you to communicate information about your extension or its content using the underlying operating system's notification service.
618 Address bar suggestions User Interface, WebExtensions
Using the omnibox API, extensions can customize the suggestions offered in the browser address bar's drop-down when the user enters a keyword.
619 Options page WebExtensions
An Options page enables you to define preferences for your extension that your users can change. Users can access the options page for an extension from the browser's add-ons manager:
620 Address bar button AddressBarButton, Page Action, User Interface, WebExtensions
Commonly referred to as a page action button, this user interface option is a button added to the browser address bar. Users click the button to interact with extensions.
621 Popups UI, User Interface, WebExtensions, popup
A popup is a dialog that's associated with a toolbar button or address bar button. This page describes popups in general, specifying them, debugging, resizing, and designing them, as well as examples of use.
622 Sidebars WebExtensions
A sidebar is a pane that is displayed at the side of the browser window, next to the web page. This page describes sidebars, specifying them, designing them, and examples of use.
623 What are extensions? Extensions, WebExtensions
An extension adds features and functions to a browser. It’s created using familiar web-based technologies—HTML, CSS, and JavaScript. It can take advantage of the same web APIs as JavaScript on a web page, but an extension also has access to its own set of JavaScript APIs. This means that you can do a lot more in an extension than you can with code in a web page. Here are just a few examples of the things you can do:
624 What next? Beginner, Extensions, WebExtension
You'll now be ready to start turning your idea for a browser extension into reality. Before you start that journey, it's worth being aware of a few things that will help to make it a smooth one.
625 Work with contextual identities Add-ons, Beginner, Contextual identities, Extensions, How-to, WebExtensions
Many people need or want to interact with the web using multiple personas. They may have accounts for web-based work and personal email. They might sign out of their social media accounts before accessing online shopping, to ensure that any tracking scripts on the shopping sites can't pick up their social media activity. To address these requirements, users often end up working with a standard and private browser window or two different browsers.
626 Work with the Bookmarks API Add-ons, Beginner, Bookmarks, Extensions, How-to, WebExtensions
Bookmarks enable users to collect and organize lists of web pages, so they can easily get back to their favorites. Using the Bookmarks API, your extensions can manipulate bookmarks in much the same way users can.
627 Work with the Cookies API Add-ons, Beginner, Cookies, Extensions, How-to, WebExtensions
With the Cookies API your extensions have access to capabilities similar to those used by websites to store and read cookies. The API’s features give extensions the ability to store information on a site-by-site basis. So, as we shall see in the example, you could store details of a user’s choice of background color for a site. Then, when the user revisits the site, your extension can use the API’s ability to get details about cookies and read them to recover the user’s choice and apply it to the website.
628 Working with files Guide, WebExtensions
Your browser extension may need to work with files to deliver its full functionality. This article looks at the five mechanisms you have for handling files:
629 Working with the Tabs API Add-ons, Beginner, Extensions, How-to, WebExtensions, tabs
Tabs let a user open several web pages in their browser window and then switch between those web pages. With the Tabs API, you can work with and manipulate these tabs to create utilities that provide users with new ways to work with tabs or to deliver the features of your extension.
630 Your first extension Add-ons, Extensions, Guide, WebExtensions
This article walks through creating an extension for Firefox, from start to finish. The extension adds a red border to any pages loaded from "mozilla.org" or any of its subdomains.
631 Your second extension WebExtensions
In this article, we'll write a slightly more complex extension that demonstrates a few more of the APIs.