Web features explorer

at-rule()

Limited availability

The at-rule() function, when used with @supports, checks if a CSS at-rule is supported. For example @supports at-rule(@starting-style) checks if the @starting-style at-rule is supported.

Browser support

  • Chrome 148 Released on 2026-05-05
  • Chrome Android 148 Released on 2026-05-05
  • Edge 148 Released on 2026-05-07
  • Firefox Not supported Position Bugs: 1751188
  • Firefox for Android Not supported Position Bugs: 1751188
  • Safari Not supported Position Bugs: 235400
  • Safari on iOS Not supported Position Bugs: 235400
👍
15

Need this feature?
Leave a 👍 on the feedback issue
Don't forget to also leave a comment explaining your specific use case.

MDN documentation

No MDN documentation found. You can search for the feature on MDN. If you believe that MDN has no documentation about this feature, you can open an issue on MDN's GitHub repository.

Specifications

Web Platform Tests (WPT)

View the latest WPT test results for this feature

View as JSON | Edit this feature | Report an issue | Web-features entry: source, dist