Web platform features explorer

:open

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

Status

Baseline Newly Available (since 2026-05-11)

This feature is expected to reach Baseline Widely Available status on: 2028-11-11

MDN documentation

Specifications

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

Interop

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