Quick Reminder That :is() and :where() Are Basically the Same With One Key Difference | CSS-Tricks

March 24, 2025

I’ve been using CSS since before the initial specification was finalised. And even way back then, CSS was 99.5% pretty straightforward, with the devil in the details. Once upon a time a lot of that was browser support gotchas, but CSS has always had subtleties that can bite.

That’s still the case now as this quick look at the :where() and :is() selectors attest.