High impact · weight 10 · worth up to 4.2 points of the total score
Google's own composite of loading, interactivity, and visual stability, measured on a simulated mid-range phone. This is the number PageSpeed Insights puts at the top of its report.
Work the opportunities below in order: they are ranked by how much loading time each one gives back.
Check a page for this, and the other 75 checks at once
Real visitors get a fast page
The Chrome UX Report measures Core Web Vitals on real Chrome users over the last 28 days, and it is the data Google's ranking uses, not the lab run. It exists only for pages, or whole sites, with enough traffic; when only the site has data, that is what this shows.
Largest Contentful Paint
LCP is the moment the biggest element in the viewport finishes rendering, which is when a visitor feels the page has arrived. Google's threshold for good is 2.5 seconds.
Cumulative Layout Shift
CLS measures content jumping around after it appears. It is why a visitor taps the wrong button when an ad or a late-loading image pushes the page down under their finger.
Interaction to Next Paint
INP is how long the page takes to visibly respond after a tap or a click. Above 200ms the interface starts to feel like it is ignoring the user. INP replaced First Input Delay (FID) as a Core Web Vital in March 2024.
