Standard metadata names

The <meta> element can be used to provide document metadata in terms of name-value pairs, with the name attribute giving the metadata name, and the content attribute giving the value.

Standard metadata names defined in the HTML specification

The HTML specification defines the following set of standard metadata names:

  • application-name: the name of the application running in the web page.

    Note:
    • Browsers may use this to identify the application. It is different from the <title> element, which usually contain the application name, but may also contain information like the document name or a status.
    • Simple web pages shouldn't define an application-name.
  • author: the name of the document's author.
  • description: a short and accurate summary of the content of the page. Several browsers, like Firefox and Opera, use this as the default description of bookmarked pages.
  • generator: the identifier of the software that generated the page.
  • keywords: words relevant to the page's content separated by commas.
  • referrer: controls the HTTP Referer header for to requests sent from the document:
    Values for the content attribute of <meta name="referrer">
    no-referrer Do not send a HTTP Referer header.
    origin Send the origin of the document.
    no-referrer-when-downgrade Send the full URL when the destination is at least as secure as the current page (HTTP(S)→HTTPS), but send no referrer when it's less secure (HTTPS→HTTP). This is the default behaviour.
    origin-when-cross-origin Send the full URL (stripped of parameters) for same-origin requests, but only send the origin for other cases.
    same-origin Send the full URL (stripped of parameters) for same-origin requests. Cross-origin requests will contain no referrer header.
    strict-origin Send the origin when the destination is at least as secure as the current page (HTTP(S)→HTTPS), but send no referrer when it's less secure (HTTPS→HTTP).
    strict-origin-when-cross-origin Send the full URL (stripped of parameters) for same-origin requests. Send the origin when the destination is at least as secure as the current page (HTTP(S)→HTTPS). Otherwise, send no referrer.
    unsafe-URL Send the full URL (stripped of parameters) for same-origin or cross-origin requests.
    Notes:
    • Dynamically inserting <meta name="referrer"> (with document.write() or appendChild()) makes the referrer behaviour unpredictable.
    • When several conflicting policies are defined, the no-referrer policy is applied.
  • theme-color: indicates a suggested color that user agents should use to customize the display of the page or of the surrounding user interface. The content attribute contains a valid CSS <color>.

Standard metadata names defined in other specifications

The CSS Color Adjustment specification defines the following metadata name:

  • color-scheme: specifies one or more color schemes with which the document is compatible.

    The browser will use this information in tandem with the user's browser or device settings to determine what colors to use for everything from background and foregrounds to form controls and scrollbars. The primary use for <meta name="color-scheme"> is to indicate compatibility with—and order of preference for—light and dark color modes.

    The value of the content property for color-scheme may be one of the following:

    normal
    The document is unaware of color schemes and should simply be rendered using the default color palette.
    [light | dark]+
    One or more color schemes supported by the document. Specifying the same color scheme more than once has the same effect as specifying it only once. Indicating multiple color schemes indicates that the first scheme is preferred by the document, but that the second specified scheme is acceptable if the user prefers it.
    only light
    Indicates that the document only supports light mode, with a light background and dark foreground colors. By specification, only dark is not valid, because forcing a document to render in dark mode when it isn't truly compatible with it can result in unreadable content; all major browsers default to light mode if not otherwise configured.

    For example, to indicate that a document prefers dark mode but does render functionally in light mode as well:

    <meta name="color-scheme" content="dark light">

    This works at the document level in the same way that the CSS color-scheme property lets individual elements specify their preferred and accepted color schemes. Your styles can adapt to the current color scheme using the prefers-color-scheme CSS media feature.

The CSS Device Adaptation specification defines the following metadata name:

  • viewport: gives hints about the size of the initial size of the viewport. Used by mobile devices only.

    Values for the content of <meta name="viewport">
    Value Possible subvalues Description
    width A positive integer number, or the text device-width Defines the pixel width of the viewport that you want the web site to be rendered at.
    height A positive integer, or the text device-height Defines the height of the viewport. Not used by any browser.
    initial-scale A positive number between 0.0 and 10.0 Defines the ratio between the device width (device-width in portrait mode or device-height in landscape mode) and the viewport size.
    maximum-scale A positive number between 0.0 and 10.0 Defines the maximum amount to zoom in. It must be greater or equal to the minimum-scale or the behaviour is undefined. Browser settings can ignore this rule and iOS10+ ignores it by default.
    minimum-scale A positive number between 0.0 and 10.0 Defines the minimum zoom level. It must be smaller or equal to the maximum-scale or the behaviour is undefined. Browser settings can ignore this rule and iOS10+ ignores it by default.
    user-scalable yes or no If set to no, the user is not able to zoom in the webpage. The default is yes. Browser settings can ignore this rule, and iOS10+ ignores it by default.
    viewport-fit auto, contain or cover

    The auto value doesn’t affect the initial layout viewport, and the whole web page is viewable.

    The contain value means that the viewport is scaled to fit the largest rectangle inscribed within the display.

    The cover value means that the viewport is scaled to fill the device display. It is highly recommended to make use of the safe area inset variables to ensure that important content doesn't end up outside the display.

    Notes:
    • Though unstandardized, this declaration is respected by most mobile browsers due to de-facto dominance.
    • The default values may vary between devices and browsers.
    • To learn about this declaration in Firefox for Mobile, see this article.
    Accessibility concerns with viewport scaling
    Disabling zooming capabilities by setting user-scalable to a value of no prevents people experiencing low vision conditions from being able to read and understand page content.
    See also

    The @viewport CSS at-rule.

Other metadata names

The WHATWG Wiki MetaExtensions page contains a large set of non-standard metadata names that have not been formally accepted yet; however, some of the names included there are already used quite commonly in practice — including the following:

  • creator: the name of the creator of the document, such as an organization or institution. If there are more than one, several <meta> elements should be used.
  • googlebot, a synonym of robots, is only followed by Googlebot (the indexing crawler for Google).
  • publisher: the name of the document's publisher.
  • robots: the behaviour that cooperative crawlers, or "robots", should use with the page. It is a comma-separated list of the values below:
    Values for the content of <meta name="robots">
    Value Description Used by
    index Allows the robot to index the page (default). All
    noindex Requests the robot to not index the page. All
    follow Allows the robot to follow the links on the page (default). All
    nofollow Requests the robot to not follow the links on the page. All
    all Equivalent to index, follow Google
    none Equivalent to noindex, nofollow Google
    noarchive Requests the search engine not to cache the page content. Google, Yahoo, Bing
    nosnippet Prevents displaying any description of the page in search engine results. Google, Bing
    noimageindex Requests this page not to appear as the referring page of an indexed image. Google
    nocache Synonym of noarchive. Bing
    Notes:
    • Only cooperative robots follow these rules. Do not expect to prevent e-mail harvesters with them.
    • The robot still needs to access the page in order to read these rules. To prevent bandwidth consumption, use a robots.txt file.
    • If you want to remove a page, noindex will work, but only after the robot visits the page again. Ensure that the robots.txt file is not preventing revisits.
    • Some values are mutually exclusive, like index and noindex, or follow and nofollow. In these cases the robot's behaviour is undefined and may vary between them.
    • Some crawler robots, like Google, Yahoo and Bing, support the same values for the HTTP header X-Robots-Tag; this allows non-HTML documents like images to use these rules.

Specifications

Specification
HTML Living Standard
The definition of 'standard metadata names' in that specification.
CSS Color Adjustment Module Level 1
The definition of 'the "color-scheme" metadata name' in that specification.
CSS Device Adaptation
The definition of 'the "viewport" metadata name' in that specification.
Referrer Policy
The definition of 'the "referrer" metadata name' in that specification.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
nameChrome Full support YesEdge Full support 12Firefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes
color-schemeChrome Full support 81Edge Full support 81Firefox No support NoIE No support NoOpera Full support 68Safari Full support 12.1WebView Android Full support 81Chrome Android Full support 81Firefox Android No support NoOpera Android No support NoSafari iOS Full support 12.2Samsung Internet Android No support No
referrerChrome Full support 17
Notes
Full support 17
Notes
Notes Until Chrome 46, content values weren't constrained to the values listed in the spec.
Edge Full support 79Firefox Full support 36
Notes
Full support 36
Notes
Notes The referrer value wasn't taken into account when navigation was happening via the context menu or middle click until Firefox 39.
IE ? Opera Full support 15
Notes
Full support 15
Notes
Notes Until Opera 46, content values weren't constrained to the values listed in the spec.
Safari ? WebView Android Full support 37
Notes
Full support 37
Notes
Notes Until Chrome 46, content values weren't constrained to the values listed in the spec.
Chrome Android Full support 18
Notes
Full support 18
Notes
Notes Until Chrome 46, content values weren't constrained to the values listed in the spec.
Firefox Android Full support 36
Notes
Full support 36
Notes
Notes The referrer value wasn't taken into account when navigation was happening via the context menu or middle click until Firefox 39.
Opera Android ? Safari iOS ? Samsung Internet Android Full support 1.0
Notes
Full support 1.0
Notes
Notes Until Samsung Internet 5.0, content values weren't constrained to the values listed in the spec.
scheme
Deprecated
Chrome Full support YesEdge Full support 12Firefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes
theme-colorChrome Partial support 73
Notes
Partial support 73
Notes
Notes Desktop Chrome only uses the color on installed progressive web apps. (Per caniuse.com.)
No support 39 — 72
Notes
Notes Desktop Chrome 39-72 claimed to have support, but did not actually use the color anywhere. Chrome for Android did use the color in the toolbar. (Per caniuse.com.)
Edge No support NoFirefox No support NoIE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android Full support 80
Notes
Full support 80
Notes
Notes Chrome for Android does not use the color on devices with native dark-mode enabled. (Per caniuse.com.)
Firefox Android No support NoOpera Android No support NoSafari iOS No support NoSamsung Internet Android Full support 6.2

Legend

Full support  
Full support
Partial support  
Partial support
No support  
No support
Compatibility unknown  
Compatibility unknown
Deprecated. Not for use in new websites.
Deprecated. Not for use in new websites.
See implementation notes.
See implementation notes.