CSSScopeRule: start property

Baseline 2025

Newly available

Since December 2025, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The start property of the CSSScopeRule interface returns a string containing the value of the @scope at-rule's scope root.

Value

A string, or null if the @scope at-rule has no scope root defined.

See the main CSSScopeRule page for an example.

Specification
CSS Cascading and Inheritance Level 6 # dom-cssscoperule-start

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`start`	Chrome – Full support Chrome 118 (Release date: 2023-10-10) footnote Full support	Edge – Full support Edge 118 (Release date: 2023-10-13) footnote Full support	Firefox – Full support Firefox 146 (Release date: 2025-12-09) footnote Full support	Opera – Full support Opera 104 (Release date: 2023-10-23) footnote Full support	Safari – Full support Safari 17.4 (Release date: 2024-03-05) footnote Full support	Chrome Android – Full support Chrome Android 118 (Release date: 2023-10-10) footnote Full support	Firefox for Android – Full support Firefox for Android 146 (Release date: 2025-12-09) footnote Full support	Opera Android – Full support Opera Android 79 (Release date: 2023-12-06) footnote Full support	Safari on iOS – Full support Safari on iOS 17.4 (Release date: 2024-03-05) footnote Full support	Samsung Internet – Full support Samsung Internet 25 (Release date: 2024-04-24) footnote Full support	WebView Android – Full support WebView Android 118 (Release date: 2023-10-10) footnote Full support	WebView on iOS – Full support WebView on iOS 17.4 (Release date: 2024-03-05) footnote Full support

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