The Chrome UX Report, or CrUX, is a public dataset of how real Chrome users experience popular websites. It collects metrics such as LCP, INP, CLS, FCP and TTFB from users who have opted in, and publishes aggregated distributions by origin and, where traffic allows, by URL. It is the field data source for PageSpeed Insights and Search Console's Core Web Vitals report.
How the data is collected
Data comes from Chrome users who have opted into usage statistics reporting and meet other eligibility conditions. Pages and origins must be publicly discoverable and have enough traffic to be included. Results are aggregated, so CrUX never shows individual visits, and data is split by device type and, in some sources, by country.
Ways to access it
Different access points serve different needs and use different time windows.
- PageSpeed Insights: a 28-day rolling view for one URL or origin
- CrUX API: the same rolling data, queryable programmatically
- CrUX History API: weekly history for trend charts
- BigQuery dataset: monthly origin-level data for large analyses
- Search Console: Core Web Vitals grouped by similar URLs
Limitations
CrUX covers only Chrome users who meet the eligibility rules, so Safari and Firefox users are not included. Low-traffic pages have no URL-level data. The 28-day window means improvements show gradually, not the day after a fix. For per-page, real-time detail, add your own real-user monitoring with a library such as web-vitals.
Example
Watching a fix roll through
Juniperforge ships an INP fix for its docs search. The CrUX History API shows the 75th percentile INP for the docs origin improving week by week over the following month, as old visits age out of the window. The team's own real-user monitoring confirmed the change the day it shipped.
Common mistakes
Expecting overnight changes
CrUX reports rolling or monthly aggregates. Allow several weeks before judging a fix.
Treating it as all your users
It covers eligible Chrome users only. Your own monitoring may show different numbers.
Questions
Yes. CrUX is public, so you can look up any origin or URL with enough traffic in PageSpeed Insights or the API.
