Is my selector sent to a server?

No. The selector is parsed entirely in your browser with plain JavaScript. Nothing you type is uploaded anywhere.

How is specificity calculated?

Specificity is a three-part score (a, b, c). a counts ID selectors, b counts classes, attribute selectors and pseudo-classes, and c counts element types and pseudo-elements. They are compared left to right, so any ID outweighs any number of classes.

How are :is(), :not() and :where() handled?

The :is(), :not() and :has() functions take the specificity of their most specific argument, while :where() always contributes zero. The calculator applies these rules and notes them in the breakdown.

CSS Specificity Calculator

Calculate the specificity of any CSS selector as an (a, b, c) score.

CSS specificity calculator

Paste any CSS selector and get its (a, b, c) specificity score: IDs first, then classes, attribute selectors and pseudo-classes, then element types and pseudo-elements. Higher a always beats higher b, which always beats higher c.

The calculator also handles the modern :is(), :not(), :has() and :where() functions and explains its reasoning. Everything is parsed in your browser, so nothing is uploaded.