Chrome User Experience Report (CrUX)
The Chrome User Experience Report is Google's public dataset of real-user performance data collected from Chrome users who have opted into URL reporting. CrUX powers PageSpeed Insights' 'Field Data' section and is the data Google uses for Core Web Vitals ranking signals. Lab tests (Lighthouse) approximate; CrUX measures reality.
Also called: CrUX, Chrome UX Report, CrUX field data · Last updated: May 27, 2026 · By Joseph W. Anady
Why it matters.
CrUX is the bridge between synthetic performance tests and real-world user experience. Lab tests in Lighthouse run in controlled environments — fast CPU, fast network, no browser extensions. CrUX captures the messy reality of users on slow phones, intermittent 4G, with browser extensions, in geographically distant locations. CrUX is what Google ranks on; Lighthouse is what developers debug with.
How it works.
Chrome collects performance data from users who have opted into reporting (default for users who haven't disabled it). The data is aggregated per origin (entire site) and per URL (individual pages) at the 75th percentile. Updates monthly. Accessible via PageSpeed Insights, the CrUX BigQuery dataset, and the CrUX API. URLs need sufficient traffic to appear (~100 visits/month minimum).
2026 reality check.
Sites with insufficient traffic don't appear in CrUX, which is why small sites can't see field data for their less-trafficked URLs. CrUX also has a known impression-overcount bug from May 2025 through April 2026 that affected GSC data. Always validate CrUX field data against direct PageSpeed Insights measurements before making major optimization decisions.
Data points
- Powered by Chrome User Experience Report (CrUX) public dataset
- Updates monthly via 28-day rolling window
- Requires ~100+ visits per URL per month for URL-level reporting
- Available via PageSpeed Insights, CrUX API, CrUX BigQuery dataset
- Google uses CrUX (not Lighthouse) for Page Experience ranking signal
First-hand insight from ThatDeveloperGuy.
ThatDeveloperGuy uses the CrUX API to monitor real-user performance across 130+ client sites. PSI baseline tracking on TDG sites shows consistent 96-99 performance scores on key landing pages. CrUX field data confirms Good status on all three Core Web Vitals for the vast majority of TDG-built pages. The few exceptions (heavy 3D background on /tools/, video-embed pages) are tracked and reviewed quarterly.
How TDG approaches it
TDG monitors CrUX field data per high-priority URL via the CrUX API, supplementing with PSI checks on URLs with insufficient field data. Quarterly review identifies regressions. Lighthouse tests in CI catch issues before deploy; CrUX validates production status post-deploy.
Common mistakes.
- Optimizing for Lighthouse score instead of CrUX field data (lab vs reality divergence)
- Ignoring URLs with insufficient CrUX data (means real-user impact is unknown)
- Treating origin-level CrUX as URL-level (origin aggregates ALL pages, can mask URL-specific problems)
- Skipping the 28-day vs 90-day CrUX window distinction (monthly aggregation has lag)
- Forgetting that CrUX measures Chrome users only (not Safari, Firefox, etc.)
FAQ.
Where can I see my CrUX data?
PageSpeed Insights at pagespeed.web.dev (paste your URL). For programmatic access: the CrUX API (free with API key) or the CrUX BigQuery dataset (free with Google Cloud).
Why doesn't my site show CrUX data?
Insufficient traffic. CrUX requires ~100+ visits per URL per month to report data. Small sites often show CrUX at the origin level but not per URL.
How often does CrUX update?
Monthly. The 28-day rolling window updates daily for the CrUX API; PSI reports use the 75th percentile of the trailing 28 days.
Is CrUX data the same as Lighthouse?
No. Lighthouse is a synthetic lab test. CrUX is real-user field data. Lighthouse approximates; CrUX measures reality. Google ranks on CrUX.
Can I opt out of CrUX measurement?
Site owners cannot. Individual Chrome users can disable 'Help improve Chrome' which removes their data from CrUX. There's no way to exclude a specific site.
Maintained by Joseph W. Anady at ThatDeveloperGuy. Back to glossary · Suggest a term