CSS :is() and :where() are coming to browsers

CSS Selectors :is() and :where() Move Toward Browser Support

Web platform news is buzzing about two upcoming pseudo-selectors, :is() and :where(), which aim to simplify how developers write complex selectors.

Cutting Repetition, Controlling Specificity

:is() primarily reduces redundancy in comma-separated selector lists. Meanwhile, :where() offers the same grouping capability but with a crucial difference: it carries no specificity weight. Notably, wrapping :not() inside :where() provides a clean way to avoid unwanted increases in selector priority—a common pitfall when using negation directly.

This advancement echoes what preprocessors have long achieved through nesting. It represents a recurring pattern: community-driven tools pioneer features, and native implementations later cement those ideas into the platform once they mature.