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Case-sensitive attribute selector

Limited availability

The s identifier in a CSS attribute selector matches attribute values case-sensitively in document languages like HTML where attribute values are case-insensitive.

Browser support

  • Chrome Not supported Bugs: 40667738
  • Chrome Android Not supported Bugs: 40667738
  • Edge Not supported Bugs: 40667738
  • Firefox 66 Released on 2019-03-19
  • Firefox for Android 66 Released on 2019-03-19
  • Safari 27 Released on 2026-09-14
  • Safari on iOS 27 Released on 2026-09-14

Baseline availability blocked since September 2026 by Chromium (1 months)

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MDN documentation

Specifications

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