Chrome User Experience Report
Google's public dataset of real-user performance measurements from opted-in Chrome users, and the official source of Core Web Vitals…
TechnicalPSI
PageSpeed Insights
Google's public tool that shows CrUX field data and a Lighthouse lab audit for a URL and its origin, side by side.
In full
PSI's top section is real-user data from CrUX and is what determines whether a URL passes Core Web Vitals; the lower section is a synthetic Lighthouse run used to diagnose why. Confusing the two is the most common misreading of the tool. An API is available for bulk monitoring, and results vary between runs because the lab test executes on shared infrastructure.
Example
A page passes the field assessment on all three vitals while scoring 42 in the lab audit, because real users are mostly on fast desktop connections.
Related terms
Lighthouse
An open-source automated auditing tool in Chrome DevTools and PageSpeed Insights that runs lab tests for performance, accessibility, best…
Core Web Vitals
Google's set of three field-measured user experience metrics — LCP, INP and CLS — used as part of the page experience signals in ranking.
Largest Contentful Paint
A Core Web Vital measuring the render time of the largest image, video poster or text block visible in the viewport; good is 2.5 s or less…
Interaction to Next Paint
A Core Web Vital measuring overall responsiveness as the latency of the worst (approximately) interaction on a page; good is 200 ms or…
Where to read more
- PageSpeed Insights · Tool Guide · pagespeed.web.dev