WEB Signal 501
CSSWG adds .prefix-* selector to Selectors Level 5 spec
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The CSS Selectors Level 5 specification now includes a .prefix-* selector that targets all classes with a hyphenated prefix, simplifying styling of prefixed class groups without attribute selectors or extra base classes.
This selector removes the need for brittle attribute selectors or extra base classes when styling prefixed utility classes in design systems. However, since it only exists in spec text and has no browser support yet, it will be years before it can be used in production.
Written by elseif from the cluster below · every claim links back to a sourceThe three things worth knowing
The Class Prefix Selector (.prefix-*) was resolved at the CSSWG F2F meeting in Berlin in August 2026 and added to the CSS Selectors Level 5 spec.
The selector only matches hyphen-separated prefixes with at least one character after the prefix, and does not match empty or double-hyphen cases.
No browser support exists yet, and feature detection is possible with @supports selector(.foo-*).
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