Core Web Vitals, load time, rendering and TTFB — from lab tests and from the Chrome users who visited your site this month.
Sample figures from an example site, mobile.
PageSpeed lab runs next to Google CrUX real-user data, so a fast test result can’t hide a slow experience.
Both form factors measured separately, because they almost never tell the same story.
Every audit is kept, so you can point at the deploy that cost you 400 milliseconds.