The CSSSupportsRule interface describes an object representing a single CSS @supports at-rule. It implements the CSSConditionRule interface, and therefore the CSSRule and CSSGroupingRule interfaces with a type value of 12 (CSSRule.SUPPORTS_RULE).


The syntax is described using the WebIDL format.

interface CSSSupportsRule : CSSConditionRule {


As a CSSConditionRule and therefore a CSSRule and a CSSGroupingRule, CSSSupportsRule also implements the properties of these interfaces. It has no specific properties.


As a CSSConditionRule and therefore a CSSRuleand a CSSGroupingRule, CSSSupportsRule also implements the methods of that interface. It has no specific methods.


Specification Status Comment
CSS Conditional Rules Module Level 3
The definition of 'CSSSupportsRule' in that specification.
Candidate Recommendation Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support No Yes171 2 No12.1 No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support No No Yes171 2 No No ?

1. From Firefox 17 to 19, methods and properties were defined on CSSSupportsRule. From version 20, they were on CSSConditionRule.

2. From version 17: this feature is behind the layout.css.supports-rule.enable preference (needs to be set to true). To change preferences in Firefox, visit about:config.

See also

Document Tags and Contributors

Contributors to this page: fscholz, mfluehr, erikadoyle, Sebastianz, teoli, kscarfone, Sheppy, webinista
Last updated by: fscholz,