Web/CSS/@supports

The @supports CSS at-rule lets you specify declarations that depend on a browser's support for one or more specific CSS features. This is called a feature query. The rule may be placed at the top level of your code or nested inside any other conditional group at-rule.

@supports (display: grid) {
  div {
    display: grid;
  }
}

@supports not (display: grid) {
  div {
    float: right;
  }
}

In JavaScript, @supports can be accessed via the CSS object model interface CSSSupportsRule.

Syntax

The @supports at-rule associates a block of statements with a supports condition. The supports condition consists of one or more name-value pairs combined by conjunctions (and), disjunctions (or), and/or negations (not). Precedence of operators can be defined with parentheses.

Declaration syntax

The most basic supports condition is a simple declaration (a property name followed by a value, separated by a colon). The declaration must be surrounded by parentheses. The following example returns true if the browser's transform-origin property considers 5% 5% valid:

@supports (transform-origin: 5% 5%) {}

Function syntax

The second basic supports condition is a supports function, the syntax for these is supported by all browsers, but the functions themselves are still being standardized.

selector()  '

Tests if the browser supports the tested selector syntax. The following example returns true if the browser supports the child combinator:

@supports selector(A > B) {}

The not operator

The not operator can precede any expression to create a new expression, resulting in the negation of the original one. The following example returns true if the browser's transform-origin property doesn't consider 10em 10em 10em valid:

@supports not (transform-origin: 10em 10em 10em) {}

As with any operator, the not operator can be applied to a declaration of any complexity. The following examples are both valid:

@supports not (not (transform-origin: 2px)) {}
@supports (display: grid) and (not (display: inline-grid)) {}

Note: There is no need to enclose the not operator between two parentheses at the top level. To combine it with other operators, like and and or, the parentheses are required.

The and operator

The and operator creates a new expression from the conjunction of two shorter expressions. It returns true only if both of the shorter expressions are also true. The following example returns true if and only if the two shorter expressions are simultaneously true:

@supports (display: table-cell) and (display: list-item) {}

Multiple conjunctions can be juxtaposed without the need of more parentheses. The following are both equivalent:

@supports (display: table-cell) and (display: list-item) and (display:run-in) {}
@supports (display: table-cell) and ((display: list-item) and (display:run-in)) {}

The or operator

The or operator creates a new expression from the disjunction of two shorter expressions. It returns true if one or both of the shorter expressions is also true. The following example returns true if at least one of the two shorter expressions is true:

@supports (transform-style: preserve) or (-moz-transform-style: preserve) {}

Multiple disjunctions can be juxtaposed without the need of more parentheses. The following are both equivalent:

@supports (transform-style: preserve) or (-moz-transform-style: preserve) or 
          (-o-transform-style: preserve) or (-webkit-transform-style: preserve) {}

@supports (transform-style: preserve-3d) or ((-moz-transform-style: preserve-3d) or
          ((-o-transform-style: preserve-3d) or (-webkit-transform-style: preserve-3d))) {}

Note: When using both and and or operators, the parentheses must be used to define the order in which they apply. Otherwise, the condition is invalid and the whole rule is ignored.

Formal syntax

@supports <supports-condition> {
  <group-rule-body>
}where <supports-condition> = not <supports-in-parens> | <supports-in-parens> [ and <supports-in-parens> ]* | <supports-in-parens> [ or <supports-in-parens> ]*where <supports-in-parens> = ( <supports-condition> ) | <supports-feature> | <general-enclosed>where <supports-feature> = <supports-decl> | <supports-selector-fn><general-enclosed> = [ <function-token> <any-value> ) ] | ( <ident> <any-value> )where <supports-decl> = ( <declaration> )<supports-selector-fn> = selector( <complex-selector> )where <complex-selector> = <compound-selector> [ <combinator>? <compound-selector> ]*where <compound-selector> = [ <type-selector>? <subclass-selector>* [ <pseudo-element-selector> <pseudo-class-selector>* ]* ]!<combinator> = '>' | '+' | '~' | [ '||' ]where <type-selector> = <wq-name> | <ns-prefix>? '*'<subclass-selector> = <id-selector> | <class-selector> | <attribute-selector> | <pseudo-class-selector><pseudo-element-selector> = ':' <pseudo-class-selector><pseudo-class-selector> = ':' <ident-token> | ':' <function-token> <any-value> ')'where <wq-name> = <ns-prefix>? <ident-token><ns-prefix> = [ <ident-token> | '*' ]?  | <id-selector> = <hash-token><class-selector> = '.' <ident-token><attribute-selector> = '[' <wq-name> ']' | '[' <wq-name> <attr-matcher> [ <string-token> | <ident-token> ] <attr-modifier>? ']'where <attr-matcher> = [ '~' |  |  | '^' | '$' | '*' ]? '='<attr-modifier> = i | s

Examples

Testing for the support of a given CSS property

@supports (animation-name: test) {
  … /* CSS applied when animations are supported without a prefix */
  @keyframes { /* Other at-rules can be nested inside */
    …
  }
}

Testing for the support of a given CSS property or a prefixed version

@supports ((perspective: 10px) or (-moz-perspective: 10px) or (-webkit-perspective: 10px) or
         (-ms-perspective: 10px) or (-o-perspective: 10px)) {
  … /* CSS applied when 3D transforms, prefixed or not, are supported */
}

Testing for the non-support of a specific CSS property

@supports not ((text-align-last: justify) or (-moz-text-align-last: justify)) {
  … /* CSS to provide fallback alternative for text-align-last: justify */
}

Testing for the support of custom properties

@supports (--foo: green) {
  body {
    color: var(--varName);
  }
}

Testing for the support of a selector (eg. :is())

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

/* This rule won't be applied in browsers which don't support :is() */
:is(ul, ol) > li {
  … /* CSS applied when the :is(…) selector is supported */
}

@supports not selector(:is(a, b)) {
  /* Fallback for when :is() is unsupported */
  ul > li,
  ol > li {
    … /* The above expanded for browsers which don't support :is(…) */
  }
}

/* Note: By far, there's no browser that supports the `of` argument of :nth-child(…) */
@supports selector(:nth-child(1n of a, b)) {
  /* This rule needs to be inside the @supports block, otherwise
     it will be partially applied in browsers which don't support
     the `of` argument of :nth-child(…) is supported */
  :is(
      :nth-child(1n of ul, ol) a,
      details > summary
  ) {
    … /* CSS applied when the :is(…) selector and
         the `of` argument of :nth-child(…) are both supported */
  }
}

Specifications

Specification	Status	Comment
CSS Conditional Rules Module Level 4The definition of '@supports' in that specification.	Editor's Draft	Adds the selector() function.
CSS Conditional Rules Module Level 3The definition of '@supports' in that specification.	Candidate Recommendation	Initial definition.

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
@supports	Chrome Full support 28	Edge Full support 12	Firefox Full support 22 Full support 22 No support 17 — 22 Disabled' Disabled' From version 17 until version 22 (exclusive): this feature is behind the layout.css.supports-rule.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support 12.1	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 28	Firefox Android Full support 22 Full support 22 No support 17 — 22 Disabled' Disabled' From version 17 until version 22 (exclusive): this feature is behind the layout.css.supports-rule.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.	Opera Android Full support 12.1	Safari iOS Full support 9	Samsung Internet Android Full support 1.5
selector()	Chrome Full support 83	Edge Full support 83	Firefox Full support 69 Full support 69 Full support 64 Disabled' Disabled' From version 64: this feature is behind the layout.css.supports-selector.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support 69	Safari No support No Notes' No support No Notes' Notes' See bug 199237	WebView Android Full support 83	Chrome Android Full support 83	Firefox Android Full support 64 Disabled' Full support 64 Disabled' Disabled' From version 64: this feature is behind the layout.css.supports-selector.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.	Opera Android No support No Notes' No support No Notes' Notes' See bug 979041.	Safari iOS No support No Notes' No support No Notes' Notes' See bug 199237	Samsung Internet Android Full support 13.0

Legend

Full support  

Full support

No support  

No support

See implementation notes.'

See implementation notes.

User must explicitly enable this feature.'

User must explicitly enable this feature.

See also

• Using feature queries
• The CSSOM class CSSSupportsRule, and the CSS.supports() method that allows the same check to be performed via JavaScript.

@supports by Mozilla Contributors is licensed under CC-BY-SA 2.5.