Web features explorer

:open

Newly Available (since 2026-05-11)
Expected to be Widely Available on 2028-11-11

The :open CSS pseudo-class matches elements that have open states, like <details>, <dialog>, or <select>, based on their state.

Browser support

  • Chrome 133 Released on 2025-02-04
  • Chrome Android 133 Released on 2025-02-04
  • Edge 133 Released on 2025-02-06
  • Firefox 136 Released on 2025-03-04
  • Firefox for Android 136 Released on 2025-03-04
  • Safari 26.5 Released on 2026-05-11
  • Safari on iOS 26.5 Released on 2026-05-11

MDN documentation

Specifications

Web Platform Tests (WPT)

View the latest WPT test results for this feature

Interop

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