Found 204 pages:

# Page Tags and summary
1 HTML HTML, HTML Lesson, HTML Programming, HTML Tutorials, HTML5, Hyper text, Hypertext, Landing, Learn, Reference, Web, What is HTML, l10n:priority
HTML (HyperText Markup Language) is the most basic building block of the Web. It describes and defines the content of a webpage. Other technologies besides HTML are generally used to describe a webpage's appearance/presentation (CSS) or functionality/behavior (JavaScript).
2 Applying color to HTML elements using CSS Beginner, CSS, CSS Colors, Guide, HTML, HTML Colors, HTML Styles, Styling HTML, color
With CSS, there lots of ways to add color to your HTML elements to create just the look you want. This article is a primer introducing each of the ways CSS color can be used in HTML.
3 Block-level elements Beginner, Development, Guide, HTML, HTML5, Web
HTML (Hypertext Markup Language) elements are usually either "block-level" elements or "inline" elements. A block-level element occupies the entire space of its parent element (container), thereby creating a "block." This article helps to explain what this means.
4 CORS enabled image Advanced, CORS, Canvas, HTML, Reference, Security
The HTML specification introduces a crossorigin attribute for images that, in combination with an appropriate CORS header, allows images defined by the <img> element that are loaded from foreign origins to be used in canvas as if they were being loaded from the current origin.
5 CORS settings attributes Advanced, CORS, HTML, NeedsContent, NeedsExample, Reference, Security
In HTML5, some HTML elements which provide support for CORS, such as <img>, <video> or <script>, have a crossorigin attribute (crossOrigin property), which lets you configure the CORS requests for the element's fetched data.
6 DASH Adaptive Streaming for HTML 5 Video Guide, HTML, HTML5
Technical review completed.
7 Global attributes Attribute, HTML, NeedsBrowserCompatibility, Reference, Web
Global attributes may be specified on all HTML elements, even those not specified in the standard. That means that any non-standard elements must still permit these attributes, even though using those elements means that the document is no longer HTML5-compliant. For example, HTML5-compliant browsers hide content marked as <foo hidden>...<foo>, even though <foo> is not a valid HTML element.
8 accesskey Global attributes, HTML, Reference
The accesskey global attribute provides a hint for generating a keyboard shortcut for the current element. This attribute consists of a space-separated list of characters (one single Unicode code point). The browser uses the first one that exists on the computer keyboard layout.
9 class Global attributes, HTML, Reference
The class global attribute is a space-separated list of the classes of the element. Classes allows CSS and Javascript to select and access specific elements via the class selectors or functions like the DOM method document.getElementsByClassName.
10 contenteditable Editing, Global attributes, HTML, Reference, Text Editing, contenteditable, text entry, text input
The contenteditable global attribute is an enumerated attribute indicating if the element should be editable by the user. If so, the browser modifies its widget to allow editing. The attribute must take one of the following values:
11 contextmenu Global attributes, HTML, Reference
The contextmenu global attribute is the id of a <menu> to use as the contextual menu for this element.
12 data-* Global attributes, HTML, Reference
The data-* global attributes form a class of attributes called custom data attributes, that allow proprietary information to be exchanged between the HTML and its DOM representation by scripts. All such custom data are available via the HTMLElement interface of the element the attribute is set on. The HTMLElement.dataset property gives access to them.
The * may be replaced by any name following the production rule of xml names with the following restrictions:
13 dir BiDi, Global attributes, HTML, Reference
The dir global attribute is an enumerated attribute indicates the directionality of the element's text. It can have the following values:
14 draggable Experimental, Global attributes, HTML, Reference
The draggable global attribute is an enumerated attribute that indicates whether the element can be dragged, using the HTML Drag and Drop API. It can have the following values:
15 dropzone Experimental, Global attributes, HTML, Reference
The dropzone global attribute is an enumerated attribute indicating what types of content can be dropped on an element, using the Drag and Drop API. It can have the following values:
16 hidden Global attributes, HTML, Reference
The hidden global attribute is a Boolean attribute indicating that the element is not yet, or is no longer, relevant. For example, it can be used to hide elements of the page that can't be used until the login process has been completed.
17 id Global attributes, HTML, Reference
The id global attribute defines a unique identifier (ID) which must be unique in the whole document. Its purpose is to identify the element when linking (using a fragment identifier), scripting, or styling (with CSS).
18 itemid Attribute, Global attribute, HTML, Microdata, Reference
The itemid global attribute is the unique, global identifier of an item. An itemid attribute can only be specified for an element that has both itemscope and itemtype attributes. Also, itemid can only be specified on elements that possess an itemscope attribute whose corresponding itemtype refers to or defines a vocabulary that supports global identifiers.
19 itemprop Attribute, Global attribute, HTML, Reference
The itemprop global attribute is used to add properties to an item. Every HTML element can have an itemprop attribute specified, and an itemprop consists of a name-value pair. Each name-value pair is called a property, and a group of one or more properties forms an item. Property values are either a string or a URL and can be associated with a very wide range of elements including <audio><embed><iframe><img><link><object><source> , <track>, and <video>.
20 itemref Attribute, Global attribute, HTML, Microdata, Reference
The global attribute itemref properties, which are not descendants of an element with the itemscope attribute, can be associated with the item using an itemref.
21 itemscope Attribute, Global attribute, HTML, Microdata, Reference
itemscope is a boolean global attribute that defines the scope of associated metadata. Specifying the itemscope attribute for an element creates a new item, which results in a number of name-value pairs that are associated with the element. A related attribute, itemtype, is used to specify the valid URL of a vocabulary (such as schema.org) that describes the item and its properties context. In each of the following examples, the vocabulary is from schema.org.
22 itemtype Attribute, Global attribute, HTML, Microdata, Reference
The global attribute itemtype specifies the URL of the vocabulary that will be used to define itemprop's (item properties) in the data structure.
23 lang Global attributes, HTML, Reference
The lang global attribute participates in defining the language of the element, the language that its non-editable elements are written in or the language that the editable elements should be written in. The tag contains one single entry value in the format defined in the Tags for Identifying Languages (BCP47) IETF document. If the tag content is the empty string the language is set to unknown; if the tag content is not valid, regarding BCP47, it is set to invalid.
24 slot Global attributes, HTML, Reference
The slot global attribute assigns a slot in a shadow DOM shadow tree to an element: An element with a slot attribute is assigned to the slot created by the <slot> element whose name attribute's value matches that slot attribute's value.
25 spellcheck Experimental, Global attributes, HTML, Reference
The spellcheck global attribute is an enumerated attribute defines whether the element may be checked for spelling errors. It may have the following values:
26 style Global attributes, HTML, Reference
The style global attribute contains CSS styling declarations to be applied to the element. Note that it is recommended for styles to be defined in a separate file or files. This attribute and the <style> element have mainly the purpose of allowing for quick styling, for example for testing purposes.
27 tabindex Global attributes, HTML, Reference
The tabindex global attribute indicates if its element can be focused, and if/where it participates in sequential keyboard navigation (usually with the Tab key, hence the name).
28 title Global attributes, HTML, Reference
The title global attribute contains text representing advisory information, related to the element it belongs to. This information can be typically, but not necessarily, presented to the user as a tooltip.
29 translate Experimental, Global attributes, HTML, Reference
The translate global attribute is an enumerated attribute that is used to specify whether an element's attribute values and the values of its Text node children are to be translated when the page is localized, or whether to leave them unchanged. It can have the following values:
30 HTML attribute reference Attribute, HTML, Reference, Web
Elements in HTML have attributes; these are additional values that configure the elements or adjust their behavior in various ways to meet the criteria the users want.
31 HTML documentation index HTML
A comprehensive index list of all the available HTML documentation.
32 HTML elements reference Basic, Element, HTML, Reference, Web, l10n:priority
This page lists all the HTML elements.
33 &lt;a&gt; Content, Element, HTML, HTML text-level semantics, Reference, Web
The HTML <a> element (or anchor element) creates a hyperlink to other web pages, files, locations within the same page, email addresses, or any other URL.
34 &lt;abbr&gt; Element, HTML, HTML text-level semantics, Reference, Web, abbr
The HTML <abbr> element represents an abbreviation and optionally provides a full description for it. If present, the title attribute must contain this full description and nothing else.
35 &lt;acronym&gt; Element, HTML, HTML:Flow content, Obsolete, Reference, Web
The HTML Acronym Element (<acronym>) allows authors to clearly indicate a sequence of characters that compose an acronym or abbreviation for a word. This element has been removed in HTML5. Use <abbr> element.
36 &lt;address&gt;: The Contact Address element Address, Author, Contact, Contact Information, Element, Email, Email Address, HTML, HTML sections, Reference, Web
The HTML <address> element indicates that the enclosed HTML provides contact information for a person or people, or for an organization.supplies contact information for its nearest <article> or <body> ancestor; in the latter case, it applies to the whole document.
37 &lt;applet&gt;: The Embed Java Applet element Element, Embedded content, HTML, HTML embedded content, Java, Obsolete, Reference, Web, applet
The obsolete HTML Applet Element (<applet>) embeds a Java applet into the document; this element has been deprecated in favor of <object>.
38 &lt;area&gt; Content, Element, HTML, Multimedia, Reference, Web, embedded
The HTML <area> element defines a hot-spot region on an image, and optionally associates it with a hypertext link. This element is used only within a <map> element.
39 &lt;article&gt;: The Article Contents element Element, HTML, HTML sections, Reference, Web
The HTML <article> element represents a self-contained composition in a document, page, application, or site, which is intended to be independently distributable or reusable (e.g., in syndication). Examples include: a forum post, a magazine or newspaper article, or a blog entry.
40 &lt;aside&gt;: The Aside element Element, HTML, HTML sections, HTML5, Reference, Web
The HTML <aside> element represents a portion of a document whose content is only indirectly related to the document's main content.
41 &lt;audio&gt;: The Embed Audio element Element, HTML, HTML embedded content, HTML5, Media, Multimedia, NeedsMobileBrowserCompatibility, Reference, Web
The HTML <audio> element is used to embed sound content in documents. It may contain one or more audio sources, represented using the src attribute or the <source> element: the browser will choose the most suitable one. It can also be the destination for streamed media, using a MediaStream.
42 &lt;b&gt;: The Bring Attention To element Attention, Element, HTML, HTML text-level semantics, HTML:Flow content, HTML:Phrasing content, Reference, Web
The HTML Bring Attention To element (<b>)  is used to draw the reader's attention to the element's contents, which are not otherwise granted special importance.
43 &lt;base&gt;: The Document Base URL element Element, HTML, HTML:Metadata content, Reference, Web
The HTML <base> element specifies the base URL to use for all relative URLs contained within a document. There can be only one <base> element in a document.
44 &lt;basefont&gt; Element, Fonts, HTML, Layout, Obsolete, Reference, Style, Web, basefont
The obsolete HTML Base Font element (<basefont>) sets a default font face, size, and color for the other elements which are descended from its parent element.
45 &lt;bdi&gt; BiDi, Element, HTML, HTML text-level semantics, Reference, Web
The HTML <bdi> element (bidirectional isolation) isolates a span of text that might be formatted in a different direction from other text outside it.
46 &lt;bdo&gt;: The Bidirectional Text Override element BiDi, Bidirectional Text, Element, HTML, HTML text-level semantics, Left to Right, NeedsCompatTable, Reference, Right to Left, Text, Text Direction, Text Rendering, Web, ltr, rtl
The HTML Bidirectional Text Override element (<bdo>) overrides the current directionality of text, so that the text within is rendered in a different direction.
47 &lt;bgsound&gt;: The Background Sound element (obsolete) Audio, Background Sound, Element, HTML, Internet Explorer, Non-standard, Obsolete, Reference, Web
The Internet Explorer only HTML Background Sound element (<bgsound>) sets up a sound file to play in the background while the page is used; use <audio> instead.
48 &lt;big&gt;: The Bigger Text element Element, HTML, Obsolete, Reference, Web
The obsolete HTML Big Element (<big>) renders the enclosed text at a font size one level larger than the surrounding text (medium becomes large, for example).
49 &lt;blink&gt;: The Blinking Text element (obsolete) Blink, Element, HTML, Obsolete, Reference, Web
The HTML Blink Element (<blink>) is a non-standard element which causes the enclosed text to flash slowly.
50 &lt;blockquote&gt;: The Block Quotation element Blockquote, Element, HTML, HTML grouping content, HTML:Flow content, Quotations, Reference, Web
The HTML <blockquote> Element (or HTML Block Quotation Element) indicates that the enclosed text is an extended quotation. Usually, this is rendered visually by indentation (see Notes for how to change it). A URL for the source of the quotation may be given using the cite attribute, while a text representation of the source can be given using the <cite> element.
51 &lt;body&gt;: The Document Body element Element, HTML, Reference, Sectioning Root Element, Sections, Web
The HTML <body> Element represents the content of an HTML document. There can be only one <body> element in a document.
52 &lt;br&gt;: The Line Break element Element, HTML, HTML text-level semantics, Reference, Web
The HTML <br> element produces a line break in text (carriage-return). It is useful for writing a poem or an address, where the division of lines is significant.
53 &lt;button&gt;: The Button element Element, Forms, HTML, HTML forms, Reference, Web
The HTML <button> element represents a clickable button, which can be used in forms, or anywhere in a document that needs simple, standard button functionality.
54 &lt;canvas&gt;: The Graphics Canvas element Canvas, Element, HTML, HTML scripting, HTML5, Reference, Web
Use the HTML <canvas> element with either the canvas scripting API or the WebGL API to draw graphics and animations.
55 &lt;caption&gt;: The Table Caption element Element, HTML, HTML Tables, HTML tabular data, NeedsExample, NeedsLiveSample, Reference, Table Captions, Table Titles, Tables, Web, caption
The HTML Table Caption element (<caption>) specifies the caption (or title) of a table, and if used is always the first child of a <table>.
56 &lt;center&gt;: The Centered Text element (obsolete) Element, HTML, Obsolete, Reference, Text, Text Alignment, Web, alignment, center
The obsolete HTML Center Element (<center>) is a block-level element that displays its block-level or inline contents centered horizontally within its containing element.
57 &lt;cite&gt;: The Citation element Attribution, Citation, Citing References, Citing Works, Element, HTML, HTML text-level semantics, Quotations, Reference, Web
The HTML Citation element (<cite>) is used to describe a reference to a cited creative work, and must include either the title or the URL of that work.
58 &lt;code&gt;: The Inline Code element Code, Element, HTML, HTML text-level semantics, Inline Code, Reference, Web
The HTML <code> element displays its contents styled in a fashion intended to indicate that the text is a short fragment of computer code.
59 &lt;col&gt; Element, HTML, HTML tabular data, Reference, Tables, Web
The HTML <col> element defines a column within a table and is used for defining common semantics on all common cells. It is generally found within a <colgroup> element.
60 &lt;colgroup&gt; Element, HTML, HTML tabular data, Reference, Tables, Web
The HTML <colgroup> element defines a group of columns within a table.
61 &lt;command&gt;: The HTML Command element Command, HTML, HTML commands, HTML5, HTML:Element, HTML:Element Reference, Obsolete
The HTML Command element (<command>) represents a command which the user can invoke. Commands are often used as part of a context menu or toolbar.
62 &lt;content&gt;: The Shadow DOM Content Placeholder element (obsolete) Content, DOM, Deprecated, Element, HTML, HTML Web Components, Placeholder, Reference, Web, Web Components, shadow dom
The HTML <content> element—an obsolete part of the Web Components suite of technologies—was used inside of Shadow DOM as an insertion point, and wasn't meant to be used in ordinary HTML.
63 &lt;data&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <data> element links a given content with a machine-readable translation. If the content is time- or date-related, the <time> element must be used.
64 &lt;datalist&gt; Element, HTML, HTML forms, HTML5, Reference, Web
The HTML <datalist> element contains a set of <option> elements that represent the values available for other controls.
65 &lt;dd&gt;: The Description Details element Definition, Description Details, Element, HTML, HTML grouping content, Reference, Web, dd, description list, details
The HTML <dd> element provides the details about or the definition of the preceding term (<dt>) in a description list (<dl>).
66 &lt;del&gt;: The Deleted Text element Deleted Text, Element, HTML, HTML edits, Reference, Web, del
The HTML <del> element represents a range of text that has been deleted from a document.
67 &lt;details&gt; Element, HTML, HTML interactive elements, Reference, Web, details
The HTML <details> element is used as a disclosure widget from which the user can retrieve additional information.
68 &lt;dfn&gt;: The Definition element Definition, Definitions, Element, HTML, HTML text-level semantics, Reference, Semantic Markup, Web, dfn
The HTML Definition element (<dfn>) is used to mark the usage instance of the enclosed term which is itself included within the definition of that term.
69 &lt;dialog&gt;: The Dialog element Dialog, Element, Experimental, HTML, HTML interactive elements, Reference, Web
The HTML <dialog> element represents a dialog box or other interactive component, such as an inspector or window.
70 &lt;dir&gt;: The Directory element (obsolete) Directory, Element, HTML, HTML Lists, HTML grouping content, Obsolete, Reference, Web, dir, lists
The obsolete HTML Directory element (<dir>) is used as a container for a directory of files and/or folders, potentially with styles and icons applied by the user agent.
71 &lt;div&gt;: The Content Division element Content Division, Element, HTML, HTML grouping content, HTML:Flow content, Layout, Reference, Web, div
The HTML Content Division element (<div>) is the generic container for flow content. It has no effect on the content or layout until styled using CSS.
72 &lt;dl&gt;: The Description List element Element, HTML, HTML grouping content, Reference, Web
The HTML <dl> element represents a description list. The element encloses a list of groups of terms (specified using the <dt> element) and descriptions. (provided by <dd> elements). Common uses for this element are to implement a glossary or to display metadata (a list of key-value pairs).
73 &lt;dt&gt;: The Description Term element Definition, Definition List, Definition Term, Element, HTML, HTML grouping content, Reference, Term, dt, lists
The HTML <dt> element specifies a term in a description or definition list, and as such must be used inside a <dl> element.
74 &lt;element&gt;: The Custom Element element (Obsolete) Element, HTML, HTML Web Components, Obsolete, Web Components, custom elements, shadow dom
The obsolete HTML <element> element was part of the Web Components specification; it was intended to be used to define new custom DOM elements.
75 &lt;em&gt;: The Emphasis element Element, HTML, HTML text-level semantics, Reference, Web, font-style
The HTML <em> element marks text that has stress emphasis. The <em> element can be nested, with each level of nesting indicating a greater degree of emphasis.
76 &lt;embed&gt;: The Embed External Content element Element, External content, HTML, HTML embedded content, HTML5, Plugins, Reference, Web, embed
The HTML <embed> element embeds external content at the specified point in the document. This content is provided by an external application or other source of interactive content such as a browser plug-in.
77 &lt;fieldset&gt;: The Field Set element Element, Forms, HTML, HTML forms, Reference, Web
The HTML <fieldset> element is used to group several controls as well as labels (<label>) within a web form.
78 &lt;figcaption&gt; Element, HTML, HTML grouping content, Reference
The HTML <figcaption> element represents a caption or a legend associated with a figure or an illustration described by the rest of the data of the <figure> element which is its immediate ancestor.
79 &lt;figure&gt; Element, HTML, HTML grouping content, Reference
The HTML <figure> element represents self-contained content, frequently with a caption (<figcaption>), and is typically referenced as a single unit.
80 &lt;font&gt; Element, HTML, Obsolete, Reference, Web
The HTML Font Element (<font>) defines the font size, color and face for its content.
81 &lt;footer&gt; Element, HTML, HTML sections, Reference
The HTML <footer> element represents a footer for its nearest sectioning content or sectioning root element. A footer typically contains information about the author of the section, copyright data or links to related documents.
82 &lt;form&gt; Element, Forms, HTML, HTML forms, Reference, Web
The HTML <form> element represents a document section that contains interactive controls to submit information to a web server.
83 &lt;frame&gt; Deprecated, Element, HTML, Reference, Web
<frame> is an HTML element which defines a particular area in which another HTML document can be displayed. A frame should be used within a <frameset>.
84 &lt;frameset&gt; Deprecated, Element, HTML, Reference, Web
<frameset> is an HTML element which is used to contain <frame> elements.
85 &lt;h1&gt;–<h6>: The HTML Section Heading elements Element, HTML, HTML sections, Reference, Web
The HTML <h1><h6> elements represent six levels of section headings. <h1> is the highest section level and <h6> is the lowest.
86 &lt;head&gt;: The Document Metadata (Header) element Element, HTML, HTML:Metadata content, Reference, Web
The HTML <head> element provides general information (metadata) about the document, including its title and links to its scripts and style sheets.
87 &lt;header&gt; Element, HTML, HTML sections, Reference
The HTML <header> element represents introductory content, typically a group of introductory or navigational aids. It may contain some heading elements but also other elements like a logo, a search form, an author name, and so on.
88 &lt;hgroup&gt; Element, Experimental, HTML, HTML sections, HTML5, Reference, Web
The HTML <hgroup> element represents a multi-level heading for a section of a document. It groups a set of <h1>–<h6> elements.
89 &lt;hr&gt;: The Thematic Break (Horizontal Rule) element Element, HTML, HTML grouping content, Reference
The HTML <hr> element represents a thematic break between paragraph-level elements (for example, a change of scene in a story, or a shift of topic with a section); historically, this has been presented as a horizontal rule or line.
90 &lt;html&gt;: The HTML Document / Root element Element, HTML, HTML Root Element, Reference, Web
The HTML <html> element represents the root (top-level element) of an HTML document, so it is also referred to as the root element. All other elements must be descendants of this element.
91 &lt;i&gt; Element, HTML, HTML text-level semantics, Reference, Web, em, font-style
The HTML <i> element represents a range of text that is set off from the normal text for some reason, for example, technical terms, foreign language phrases, or fictional character thoughts. It is typically displayed in italic type.
92 &lt;iframe&gt; Content, Element, HTML, Reference, Web, embedded
The HTML <iframe> element represents a nested browsing context, effectively embedding another HTML page into the current page. In HTML 4.01, a document may contain a head and a body or a head and a frameset, but not both a body and a frameset. However, an <iframe> can be used within a normal document body. Each browsing context has its own session history and active document. The browsing context that contains the embedded content is called the parent browsing context. The top-level browsing context (which has no parent) is typically the browser window.
93 &lt;image&gt; Element, HTML, HTML Element Reference, HTML Reference, HTML element, Non-standard, Obsolete, Reference
The HTML <image> element is an obsolete remnant of an ancient version of HTML lost in the mists of time; use the standard <img> element instead. Seriously, the specification even literally uses the words "Don't ask" when describing this element.
94 &lt;img&gt;: The Image Embed element Content, Element, Graphics, HTML, Image, Multimedia, Reference, Web, embedded
The HTML <img> element embeds an image into the document.
95 &lt;input&gt; Data entry, Element, Forms, HTML, HTML forms, HTML input tag, Input, MakeBrowserAgnostic, NeedsBrowserCompatibility, NeedsMobileBrowserCompatibility, Reference, Web
The HTML <input> element is used to create interactive controls for web-based forms in order to accept data from the user.
96 &lt;input type="button"&gt; Element, Forms, HTML, HTML forms, Input, Input Element, Input Type, Reference, button
<input> elements of type "button"  are rendered as simple push buttons, which can be programmed to control custom functionality anywhere on a webpage as required when assigned an event handler function (typically for the click event).
97 &lt;input type="checkbox"&gt; Element, HTML, HTML forms, Input, Input Types, Reference, checkbox, form
<input> elements of type checkbox are rendered by default as square boxes that are checked (ticked) when activated, like you might see in an official government paper form. They allow you to select single values for submission in a form (or not).
98 &lt;input type="color"&gt; Color Picker, Element, Form input, Forms, HTML, HTML forms, HTML input, Input, Reference, color
<input> elements of type "color" provide a user interface element that lets a user specify a color, either by using a visual color picker interface or by entering the color into a text field in "#rrggbb" hexadecimal format.
99 &lt;input type="date"&gt; Date, Date picker, Element, Form Inputs, HTML, HTML forms, Input, Input Element, Input Type, Reference
<input> elements of type date create input fields that let the user enter a date, either using a text box that automatically validates the content, or using a special date picker interface. The resulting value includes the year, month, and day, but not the time. The time and datetime-local input types support time and date/time inputs.
100 &lt;input type="datetime"&gt; Element, HTML, HTML forms, Input, Input Element, Input Type, Obsolete, Reference, datetime
The HTML <input type="datetime"> was a control for entering a date and time (hour, minute, second, and fraction of a second) as well as a timezone. This feature has been removed from WHATWG HTML, and is no longer supported in browsers.
101 &lt;input type="datetime-local"&gt; Date, Date and Time, Element, Form input, HTML, HTML forms, Input, Input Element, Input Type, Reference, Time, datetime-local
<input> elements of type datetime-local create input controls that let the user easily enter both a date and a time, including the year, month, and day as well as the time in hours and minutes. The user's local time zone is used.
102 &lt;input type="email"&gt; Email, Forms, HTML, HTML forms, Input Type, Reference
<input> elements of type "email" are used to let the user enter and edit an email address, or, if the multiple attribute is specified, a list of email addresses. The input value is automatically validated to ensure that it's either empty or a properly-formatted email address (or list of addresses) before the form can be submitted.
103 &lt;input type="file"&gt; Directory Picker, File, File Picker, Files, Form input, HTML, HTML forms, Input Type, Reference, Type
<input> elements with type="file" let the user choose one or more files from their device storage. Once chosen, the files can be uploaded to a server using form submission, or manipulated using JavaScript code and the File API.
104 &lt;input type="hidden"&gt; Element, Forms, HTML, HTML forms, Input, Input Types, Reference, hidden
<input> elements of type "hidden" let web developers include data that cannot be seen or modified by users when a form is submitted. For example, the ID of the content that is currently being ordered or edited, or a unique security token. Hidden inputs are completely invisible in the rendered page, and there is no way to make it visible in the page's content.
105 &lt;input type="image"&gt; Element, Forms, HTML, HTML forms, Input, Input Type, Number, Reference
<input> elements of type "image" are used to create graphical submit buttons, i.e. submit buttons that take the form of an image rather than text.
106 &lt;input type="month"&gt; Date picker, Element, Form input, Forms, HTML, HTML forms, HTML input, Input, Input Element, Input Type, Number, Reference, month
<input> elements of type month create input fields that let the user enter a month and year allowing a month and year to be easily entered. The value is a string whose value is in the format "YYYY-MM", where YYYY is the four-digit year and MM is the month number.
107 &lt;input type="number"&gt; Element, Forms, HTML, HTML forms, Input, Input Element, Input Type, Number, Reference
<input> elements of type "number" are used to let the user enter a number. They include built-in validation to reject non-numerical entries.
108 &lt;input type="password"&gt; Element, Forms, HTML, HTML Input Types, HTML Inputs, HTML Password Input, HTML forms, HTML input tag, Input Types, NeedsBrowserCompatibility, NeedsMobileBrowserCompatibility, Reference, Web, password
<input> elements of type "password" provide a way for the user to securely enter a password.
109 &lt;input type="radio"&gt; Choosing Options, Element, Form Options, HTML, HTML Input Types, HTML forms, HTML input, Input, Input Types, Options, Radio Buttons, Radio Groups, Reference, form, radio, radio button
<input> elements of type radio are generally used in radio groups—collections of radio buttons describing a set of related options.
110 &lt;input type="range"&gt; Element, Forms, HTML forms, HTML input tag, Input, Range, Reference, Web, slider
<input> elements of type "range" let the user specify a numeric value which must be no less than a given value, and no more than another given value. The precise value, however, is not considered important. This is typically represented using a slider or dial control rather than a text entry box like the "number" input type.
111 &lt;input type="reset"&gt; Element, Form Button, Form input, Forms, HTML, HTML forms, Input, Input Types, Reference, Reset Button, reset
<input> elements of type "reset"  are rendered as buttons, with a default click event handler that resets all of the inputs in the form to their initial values.
112 &lt;input type="search"&gt; Form input, Forms, HTML, HTML forms, Input Type, Reference, Search
<input> elements of type "search" are text fields designed for the user to enter search queries into. These are functionally identical to text inputs, but may be styled differently by the user agent.
113 &lt;input type="submit"&gt; Element, Form Button, Form input, HTML, HTML forms, Input, Input Types, Reference, Submit Form, button, form, submit, submit button
<input> elements of type "submit" are rendered as buttons. When the click event occurs (typically because the user clicked the button), the user agent attempts to submit the form to the server.
114 &lt;input type="tel"&gt; Element, Form Inputs, Forms, HTML, HTML forms, HTML input, Input, Input Element, Input Type, Phone Numbers, Reference, Telephone Numbers, tel
<input> elements of type "tel" are used to let the user enter and edit a telephone number. Unlike <input type="email"> and <input type="url"> , the input value is not automatically validated to a particular format before the form can be submitted, because formats for telephone numbers vary so much around the world.
115 &lt;input type="text"&gt; Form input, Forms, HTML, HTML forms, Input, Input Type, Reference, Text, text entry, text input
<input> elements of type "text" create basic single-line text fields.
116 &lt;input type="time"&gt; Element, Forms, HTML, HTML Input Types, HTML forms, HTML input, Input, Input Element, Input Type, Reference, Time
<input> elements of type time create input fields designed to let the user easily enter a time (hours and minutes, and optionally seconds).
117 &lt;input type="url"&gt; Element, Form Inputs, Forms, HTML, HTML Input Types, HTML forms, Input, Input Type, Reference, URL
<input> elements of type "url" are used to let the user enter and edit a URL. The input value is automatically validated to ensure that it's either empty or a properly-formatted URL before the form can be submitted.
118 &lt;input type="week"&gt; Element, Forms, HTML, HTML Input Types, HTML forms, HTML input, Input, Input Element, Input Type, Input Types, Reference, Week, Weeks
<input> elements of type "week" create input fields allowing easy entry of a year plus the number of the week during that year (e.g. week 1 to 52).
119 &lt;ins&gt; Element, HTML, HTML edits, Reference, Web
The HTML <ins> element represents a range of text that has been added to a document.
120 &lt;isindex&gt; Deprecated, Element, HTML, Reference, Web
<isindex> is an obsolete HTML element that puts a text field in a page for querying the document.
121 &lt;kbd&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <kbd> element represents user input and produces an inline element displayed in the browser's default monospace font.
122 &lt;keygen&gt; Deprecated, Element, HTML, HTML forms, HTML5, Reference, Web
The HTML <keygen> element exists to facilitate generation of key material, and submission of the public key as part of an HTML form. This mechanism is designed for use with Web-based certificate management systems. It is expected that the <keygen> element will be used in an HTML form along with other information needed to construct a certificate request, and that the result of the process will be a signed certificate.
123 &lt;label&gt; Element, Forms, HTML, HTML forms, Reference, Web
The HTML <label> element represents a caption for an item in a user interface.
124 &lt;legend&gt; Element, Forms, HTML, HTML forms, Reference, Web
The HTML <legend> element represents a caption for the content of its parent <fieldset>.
125 &lt;li&gt; Element, HTML, HTML grouping content, Reference
The HTML <li> element is used to represent an item in a list. It must be contained in a parent element: an ordered list (<ol>), an unordered list (<ul>), or a menu (<menu>). In menus and unordered lists, list items are usually displayed using bullet points. In ordered lists, they are usually displayed with an ascending counter on the left, such as a number or letter.
126 &lt;link&gt;: The External Resource Link element Element, HTML, HTML document metadata, Reference, Web, metadata
The HTML <link> element specifies relationships between the current document and an external resource. Possible uses for this element include defining a relational framework for navigation. This element is most used to link to style sheets.
127 &lt;listing&gt; Element, HTML, Obsolete, Reference, Web
The HTML Listing Element (<listing>) renders text between the start and end tags without interpreting the HTML in between and using a monospaced font. The HTML 2 standard recommended that lines shouldn't be broken when not greater than 132 characters.
128 &lt;main&gt; Element, HTML, HTML grouping content, Reference, main
The HTML <main> element represents the main content of the <body> of a document, portion of a document, or application. The main content area consists of content that is directly related to, or expands upon the central topic of, a document or the central functionality of an application.
129 &lt;map&gt; Element, HTML, HTML embedded content, Multimedia, Reference, Web
The HTML <map> element is used with <area> elements to define an image map (a clickable link area).
130 &lt;mark&gt; Element, HTML, HTML text-level semantics, HTML5, Reference, Web
The HTML <mark> element represents highlighted text, i.e., a run of text marked for reference purpose, due to its relevance in a particular context.
131 &lt;marquee&gt; Element, HTML, Obsolete, Reference, Web, marquee
The HTML <marquee> element is used to insert a scrolling area of text. You can control what happens when the text reaches the edges of its content area using its attributes.
132 &lt;menu&gt; Element, Experimental, HTML, HTML interactive elements, Reference, UX, Web, menus
The HTML <menu> element represents a group of commands that a user can perform or activate. This includes both list menus, which might appear across the top of a screen, as well as context menus, such as those that might appear underneath a button after it has been clicked.
133 &lt;menuitem&gt; Element, Experimental, HTML, HTML interactive elements, HTML5, Reference, Web
The HTML <menuitem> element represents a command that a user is able to invoke through a popup menu. This includes context menus, as well as menus that might be attached to a menu button.
134 &lt;meta&gt;: The Document-level Metadata element Document, Element, HTML, HTML document metadata, Reference, Web, metadata
The HTML <meta> element represents metadata that cannot be represented by other HTML meta-related elements, like <base>, <link>, <script>, <style> or <title>.
135 &lt;meter&gt; Element, HTML, HTML forms, HTML5, Reference, Web
The HTML <meter> element represents either a scalar value within a known range or a fractional value.
136 &lt;multicol&gt; Element, HTML, Non-standard, Obsolete, Reference, multicol
The HTML <multicol> element was an experimental element designed to allow multi-column layouts. It never got any significant traction and is not implemented in any major browsers.
137 &lt;nav&gt;: The Navigation Section element Element, HTML, HTML sections, Links, Navigation, Reference, Sections, Web, nav
The HTML <nav> element represents a section of a page whose purpose is to provide navigation links, either within the current document or to other documents. Common examples of navigation sections are menus, tables of contents, and indexes.
138 &lt;nextid&gt;: The NeXT ID element (Obsolete) Element, HTML, Obsolete, Reference, Web
<nextid> is an obsolete HTML element that served to enable the NeXT web designing tool to generate automatic NAME labels for its anchors.
139 &lt;nobr&gt;: The Non-Breaking Text element (obsolete) Element, HTML, HTML text-level semantics, Non-standard, Obsolete, Reference, Web, nobr
The non-standard, obsolete HTML <nobr> element prevents the text it contains from automatically wrapping accross multiple lines, potentially resulting in the user having to scroll horizontally to see the entire width of the text.
140 &lt;noembed&gt;: The Embed Fallback element (Obsolete) Element, Embedded content, Embedding, HTML, HTML embedded content, Non-standard, Obsolete, Reference, noembed
The <noembed> element is an obsolete, non-standard way to provide alternative, or "fallback", content for browsers that do not support the <embed> element or do not support the type of embedded content an author wishes to use.
141 &lt;noframes&gt;: The Frame Fallback element Element, Frames, HTML, HTML frames, Obsolete, Reference, Web, noframes
The obsolete HTML No Frames or frame fallback element, <noframes>, provides content to be presented in browsers that don't support (or have disabled support for) the <frame> element.
142 &lt;noscript&gt; Element, HTML, HTML scripting, Reference, Web
The HTML <noscript> element defines a section of HTML to be inserted if a script type on the page is unsupported or if scripting is currently turned off in the browser.
143 &lt;object&gt; Element, HTML, HTML embedded content, Reference, Web
The HTML <object> element represents an external resource, which can be treated as an image, a nested browsing context, or a resource to be handled by a plugin.
144 &lt;ol&gt;: The Ordered List element Element, HTML, HTML grouping content, HTML:Flow content, Reference
The HTML <ol> element represents an ordered list of items, typically rendered as a numbered list.
145 &lt;optgroup&gt; Element, Forms, HTML, HTML forms, Reference, Web
The HTML <optgroup> element creates a grouping of options within a <select> element.
146 &lt;option&gt; Element, Forms, HTML, HTML forms, Reference, Web
The HTML <option> element is used to define an item contained in a <select>, an <optgroup>, or a <datalist> element. As such, <option> can represent menu items in popups and other lists of items in an HTML document.
147 &lt;output&gt;: The Output element Element, HTML, HTML forms, HTML5, HTML:Flow content, NeedsMobileBrowserCompatibility, Reference, Web
The HTML Output element (<output>) is a container element into which a site or app can inject the results of a calculation or the outcome of a user action.
148 &lt;p&gt;: The Paragraph element Element, HTML, HTML grouping content, Reference, Web
The HTML <p> element represents a paragraph of text.
149 &lt;param&gt;: The Object Parameter element Element, HTML, HTML embedded content, Reference, Web
The HTML <param> element defines parameters for an <object> element.
150 &lt;picture&gt;: The Picture element Element, Graphics, HTML, HTML embedded content, Images, Reference, Web, picture
The HTML <picture> element serves as a container for zero or more <source> elements and one <img> element to provide versions of an image for different display device scenarios.
151 &lt;plaintext&gt;: The Plain Text element (Deprecated) Element, HTML, NeedsCompatTable, Obsolete, Reference, Web
The HTML Plaintext Element (<plaintext>) renders everything following the start tag as raw text, without interpreting any HTML. There is no closing tag, since everything after it is considered raw text.
152 &lt;pre&gt;: The Preformatted Text element Element, HTML, HTML grouping content, HTML:Flow content, Reference, Web
The HTML <pre> element represents preformatted text which is to be presented exactly as written in the HTML file.
153 &lt;progress&gt;: The Progress Indicator element Element, HTML, HTML forms, HTML5, Reference, Web
The HTML <progress> element displays an indicator showing the completion progress of a task, typically displayed as a progress bar.
154 &lt;q&gt;: The Inline Quotation element Citation, Cite, Element, HTML, HTML text-level semantics, Q, Quotation, Quotation Marks, Reference, Web, quote
The HTML <q> element indicates that the enclosed text is a short inline quotation. Most modern browsers implement this by surrounding the text in quotation marks.
155 &lt;rp&gt;: The Ruby Fallback Parenthesis element Element, HTML, HTML text-level semantics, Reference, Ruby, Text, Web
The HTML Ruby Fallback Parenthesis (<rp>) element is used to provide fall-back parentheses for browsers that do not support display of ruby annotations using the <ruby> element.
156 &lt;rt&gt;: The Ruby Text element Element, HTML, HTML text-level semantics, Reference, Ruby, Text, Web
The HTML Ruby Text (<rt>) element specifies the ruby text component of a ruby annotation, which is used to provide pronunciation, translation, or transliteration information for East Asian typography. The <rt> element must always be contained within a <ruby> element.
157 &lt;rtc&gt;: The Ruby Text Container element Element, HTML, HTML text-level semantics, NeedsContent, Reference, Ruby Text, Text, Web, rtc
The HTML Ruby Text Container (<rtc>) element embraces semantic annotations of characters presented in a ruby of <rb> elements used inside of <ruby> element. <rb> elements can have both pronunciation (<rt>) and semantic (<rtc>) annotations.
158 &lt;ruby&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <ruby> element represents a ruby annotation. Ruby annotations are for showing pronunciation of East Asian characters.
159 &lt;s&gt; Element, HTML, HTML text-level semantics, NeedsNewBrowserCompatTable, Reference, Web, text-decoration
The HTML <s> element renders text with a strikethrough, or a line through it. Use the <s> element to represent things that are no longer relevant or no longer accurate. However, <s> is not appropriate when indicating document edits; for that, use the <del> and <ins> elements, as appropriate.
160 &lt;samp&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <samp> element is an element intended to identify sample output from a computer program. It is usually displayed in the browser's default monotype font (such as Lucida Console).
161 &lt;script&gt;: The Script element Element, HTML, HTML scripting, HTML:Flow content, HTML:Metadata content, HTML:Phrasing content, HTML:Script-supporting element, Reference, Script, Web
The HTML <script> element is used to embed or reference executable code; this is typically used to embed or refer to JavaScript code.
162 &lt;section&gt;: The Generic Section element Element, HTML, HTML sections, Reference, Web
The HTML <section> element represents a standalone section — which doesn't have a more specific semantic element to represent it — contained within an HTML document.
163 &lt;select&gt; Element, Forms, HTML, HTML forms, Reference, Web, events
The HTML <select> element represents a control that provides a menu of options:
164 &lt;shadow&gt; Element, HTML, HTML Web Components, Obsolete, Reference, Web Components, shadow, shadow dom
The HTML <shadow> element—an obsolete part of the Web Components technology suite—was intended to be used as a shadow DOM insertion point. You might have used it if you have created multiple shadow roots under a shadow host. It is not useful in ordinary HTML.
165 &lt;slot&gt; Element, HTML, HTML Web Components, Reference, Web Components, shadow dom, slot
The HTML <slot> element—part of the Web Components technology suite—is a placeholder inside a web component that you can fill with your own markup, which lets you create separate DOM trees and present them together.
166 &lt;small&gt; Element, HTML, HTML text-level semantics, Reference, Web, font-size
The HTML <small> element makes the text font size one size smaller (for example, from large to medium, or from small to x-small) down to the browser's minimum font size.  In HTML5, this element is repurposed to represent side-comments and small print, including copyright and legal text, independent of its styled presentation.
167 &lt;source&gt; Element, HTML, HTML embedded content, MakeBrowserAgnostic, Media, Reference, Web
The HTML <source> element specifies multiple media resources for the <picture>, the <audio> element, or the <video> element. It is an empty element. It is commonly used to serve the same media content in multiple formats supported by different browsers.
168 &lt;spacer&gt; Element, HTML, NeedsBrowserCompatibility, Obsolete, Reference, Web
<spacer> is an obsolete HTML element which allowed insertion of empty spaces on pages. It was devised by Netscape to accomplish the same effect as a single-pixel layout image, which was something web designers used to use to add white spaces to web pages without actually using an image. However, <spacer> no longer supported by any major browser and the same effects can now be achieved using simple CSS.
169 &lt;span&gt; Element, HTML, HTML text-level semantics, HTML:Flow content, Reference, Web
The HTML <span> element is a generic inline container for phrasing content, which does not inherently represent anything. It can be used to group elements for styling purposes (using the class or id attributes), or because they share attribute values, such as lang.
170 &lt;strike&gt; Element, HTML, Obsolete, Reference, Web
The HTML <strike> element (or HTML Strikethrough Element) places a strikethrough (horizontal line) over text.
171 &lt;strong&gt; Element, HTML, HTML text-level semantics, Reference, Web, font-weight
The HTML <strong> element gives text strong importance and is typically displayed in bold.
172 &lt;style&gt;: The Style Information element CSS, Element, HTML, HTML document metadata, Reference, Style, Web
The HTML <style> element contains style information for a document, or part of a document.
173 &lt;sub&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <sub> element defines a span of text that should be displayed, for typographic reasons, lower, and often smaller, than the main span of text.
174 &lt;summary&gt; Element, HTML, HTML interactive elements, Reference, Web
The HTML <summary> element is used as a summary, caption, or legend for the content of a <details> element.
175 &lt;sup&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <sup> element defines a span of text that should be displayed, for typographic reasons, higher, and often smaller, than the main span of text.
176 &lt;table&gt;: The Table element CSS, Element, HTML, HTML tabular data, Reference, Tables, Web
The HTML <table> element represents tabular data — that is, information presented in a two-dimensional table comprised of rows and columns of cells containing data.
177 &lt;tbody&gt; Element, HTML, HTML tabular data, Reference, Tables, Web
The HTML <tbody> element groups one or more <tr> elements as the body of a <table> element.
178 &lt;td&gt;: The Table Data Cell element Cells, Data Cell, Element, HTML, HTML tabular data, Reference, Table Cell, Table Data, Tables, Web, cell, data, td
The HTML <td> element defines a cell of a table that contains data. It participates in the table model.
179 &lt;template&gt; Element, HTML, HTML Web Components, HTML:Flow content, HTML:Metadata content, HTML:Phrasing content, HTML:Script-supporting element, Reference, Template, Web, Web Components
The HTML <template> element is a mechanism for holding client-side content that is not to be rendered when a page is loaded but may subsequently be instantiated during runtime using JavaScript.
180 &lt;textarea&gt; Element, Forms, HTML, HTML forms, Reference, Web, textarea
The HTML <textarea> element represents a multi-line plain-text editing control.
181 &lt;tfoot&gt; Element, HTML, HTML tabular data, Reference, Tables, Web
The HTML <tfoot> element defines a set of rows summarizing the columns of the table.
182 &lt;th&gt; Element, HTML, HTML tabular data, Reference, Tables, Web
The HTML <th> element defines a cell as header of a group of table cells. The exact nature of this group is defined by the scope and headers attributes.
183 &lt;thead&gt; Element, HTML, HTML tabular data, Reference, Tables, Web
The HTML <thead> element defines a set of rows defining the head of the columns of the table.
184 &lt;time&gt; Element, HTML, HTML text-level semantics, HTML5, Reference, Web
The HTML <time> element represents either a time on a 24-hour clock or a precise date in the Gregorian calendar (with optional time and timezone information).
185 &lt;title&gt;: The Document Title element Element, HTML, HTML:Metadata content, Reference, Web
The HTML <title> element defines the title of the document, shown in a browser's title bar or on the page's tab. It can only contain text, and any contained tags are ignored.
186 &lt;tr&gt;: The Table Row element Element, HTML, HTML tabular data, Reference, Tables, Web, tag, tr, tr tag
The HTML <tr> element specifies that the markup contained inside the <tr> block comprises one row of a table, inside which the <th> and <td> elements create header and data cells, respectively, within the row.
187 &lt;track&gt; Element, HTML, HTML embedded content, HTML5, Multimedia, Reference, Web
The HTML <track> element is used as a child of the media elements <audio> and <video>. It lets you specify timed text tracks (or time-based data), for example to automatically handle subtitles. The tracks are formatted in WebVTT format (.vtt files) — Web Video Text Tracks.
188 &lt;tt&gt; Element, HTML, Obsolete, Reference, Web
The HTML Teletype Text Element (<tt>) produces an inline element displayed in the browser's default monotype font. This element was intended to style text as it would display on a fixed width display, such as a teletype. It probably is more common to display fixed width type using the <code> element.
189 &lt;u&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <u> element renders text with an underline, a line under the baseline of its content. In HTML5, this element represents a span of text with an unarticulated, though explicitly rendered, non-textual annotation, such as labeling the text as being a proper name in Chinese text (a Chinese proper name mark), or labeling the text as being misspelled.
190 &lt;ul&gt; Element, HTML, HTML grouping content, Reference
The HTML <ul> element represents an unordered list of items, typically rendered as a bulleted list.
191 &lt;var&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <var> element represents a variable in a mathematical expression or a programming context.
192 &lt;video&gt; Element, HTML, HTML embedded content, HTML5, Media, Multimedia, NeedsMobileBrowserCompatibility, Reference, Web
Use the HTML <video> element to embed video content in a document.
193 &lt;wbr&gt; Element, HTML, HTML text-level semantics, Reference, Web
The HTML <wbr> element represents a word break opportunity—a position within text where the browser may optionally break a line, though its line-breaking rules would not otherwise create a break at that location.
194 &lt;xmp&gt; Element, HTML, Obsolete, Reference, Web
The HTML Example Element (<xmp>) renders text between the start and end tags without interpreting the HTML in between and using a monospaced font. The HTML2 specification recommended that it should be rendered wide enough to allow 80 characters per line.
195 HTML reference HTML, Landing, Reference, Web
This HTML reference describes all elements and attributes of HTML, including global attributes that apply to all elements.
196 Inline elements Beginner, Elements, HTML, HTML Elements, HTML:Element Reference, Inline elements, Layout, Reference
In HTML, inline elements are those which only occupy the space bounded by the tags defining the element, instead of breaking the flow of the content.
197 Link types HTML, Link, Link types, Reference
In HTML, the following link types indicate the relationship between two documents, in which one links to the other using an <a>, <area>, or <link> element.
198 Media formats for HTML audio and video Codecs, Containers, Firefox, HTML, HTML5, Media, Reference, Video, file formats, media formats
The <audio> and <video> elements provide support for playing audio and video without plug-ins.
199 Microdata Composing, Example, HTML, Microdata, Reference, SEO, Search
Microdata is a WHATWG HTML specification used to nest metadata within existing content on web pages.[1] Search engines, web crawlers, and browsers can extract and process microdata from a web page and use it to provide a richer browsing experience for users. Search engines benefit greatly from direct access to this structured data because it allows search engines to understand the information on web pages and provide more relevant results to users. Microdata uses a supporting vocabulary to describe an item and name-value pairs to assign values to its properties. Microdata is an attempt to provide a simpler way of annotating HTML elements with machine-readable tags than the similar approaches of using RDFa and microformats.
200 Microformats HTML, NeedsContent, NeedsMarkupWork
Microformats (sometimes abbreviated μF) are simple conventions used to embed semantics in HTML and quickly provide an API to be used by search engines, aggregators, and other tools. These small patterns of HTML are used for marking entities that range from fundamental to domain-specific information, such as people, organizations, events, and locations.
201 Optimizing your pages for speculative parsing Advanced, HTML, HTML5, NeedsUpdate, Web Development
Traditionally in browsers the HTML parser has run on the main thread and is blocked after a </script> tag until the script has been retrieved from the network and executed. The HTML parser in Firefox 4 and later supports speculative parsing off of the main thread. It parses ahead while scripts are being downloaded and executed. As in Firefox 3.5 and 3.6, the HTML parser starts speculative loads for scripts, style sheets and images it finds ahead in the stream. However, in Firefox 4 and later the HTML parser also runs the HTML tree construction algorithm speculatively. The upside is that when a speculation succeeds, there's no need to reparse the part of the incoming file that was already scanned for scripts, style sheets and images. The downside is that there's more work lost when the speculation fails.
202 Preloading content with rel="preload" Guide, HTML, JavaScript, Link, Media, Performance, as, preload, rel
The preload value of the <link> element's rel attribute allows you to write declarative fetch requests in your HTML <head>, specifying resources that your pages will need very soon after loading, which you therefore want to start preloading early in the lifecycle of a page load, before the browser's main rendering machinery kicks in. This ensures that they are made available earlier and are less likely to block the page's first render, leading to performance improvements. This article provides a basic guide to how preload works.
203 Quirks Mode and Standards Mode Gecko, Guide, HTML, NeedsUpdate, Web Development, Web Standards, XHTML
In the old days of the web, pages were typically written in two versions: One for Netscape Navigator, and one for Microsoft Internet Explorer. When the web standards were made at W3C, browsers could not just start using them, as doing so would break most existing sites on the web. Browsers therefore introduced two modes to treat new standards compliant sites differently from old legacy sites.
204 Using the application cache Advanced, App, Cache, Guide, HTML, appcache, application cache, web cache
HTML5 provides an application caching mechanism that lets web-based applications run offline. Developers can use the Application Cache (AppCache) interface to specify resources that the browser should cache and make available to offline users. Applications that are cached load and work correctly even if users click the refresh button when they are offline.
A comprehensive index list of all the available HTML documentation.

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 Contributors to this page: heyDante, escattone, pururval, fscholz
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