Quick Reminder That :is() and :where() Are Basically the Same With One Key Difference | CSS-Tricks
March 24, 2025

I’ve seen a handful of recent posts talking about the utility of the :is() relational pseudo-selector. No need to delve into the details other than to say it can help make compound selectors a lot more readable.
Source: Quick Reminder That :is() and :where() Are Basically the Same With One Key Difference | CSS-Tricks
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.