Chrome UX Report (CrUX)
TL;DR
CrUX provides real-world performance data from actual Chrome users — not lab simulations. Google uses CrUX data directly in its ranking algorithm.
Explain Simply
Lighthouse is like a driving test on a closed course. CrUX is like monitoring how drivers actually perform on real roads. Google cares more about real road performance.
Chrome UX Report (CrUX) is a public dataset of real user experience metrics collected from opted-in Chrome users. CrUX provides real-world Core Web Vitals metrics (LCP, FID/INP, CLS) per origin or URL.
CrUX data is collected over a rolling 28-day period. A URL needs sufficient traffic to have URL-level data; otherwise, only origin-level (whole-domain) data is available. Metrics are reported at the 75th percentile (p75) — meaning 75% of page loads must meet the 'good' threshold.
CrUX is available via the CrUX API, BigQuery public dataset, PageSpeed Insights (field data section), and Search Console (Core Web Vitals report). The API returns data for LCP, INP, CLS, FCP, TTFB, and experimental metrics.
⚡Why It Matters
Unlike lab data (Lighthouse), CrUX reflects real user experience. Google uses CrUX data to evaluate page experience in its ranking algorithm. Sites with insufficient CrUX data miss out on page experience ranking signals entirely.
🔍How AiSEO Checks
AiSEO queries the CrUX API to get real-world data on LCP, FID, CLS, TTFB for the audited URL or origin.
AiSEO Score Impact
Up to 1 point in the Performance category (15% of total score) — bonus for having CrUX field data available
Fix Difficulty
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