Chrome User
Experience Report
Analyze real-world CrUX performance metrics from millions of websites over the last 6 months. Core Web Vitals trends, distributions, and form-factor breakdown from actual Chrome users.
What's in the report
Diagnose Core Web Vitals with real Chrome data
Performance Score
Instant health assessment
A 0–100 score derived from real Chrome user data at the 75th percentile. Pinpoints your biggest bottleneck and surfaces quick wins across all Core Web Vitals.
Web Vitals
Six metrics at the P75
LCP, INP, CLS, FCP, TTFB, and RTT — each with current P75 values, pass/fail status, and 6-month trend direction so you know exactly what changed.
Trends
6-month P75 trend lines
Color-coded charts with good/poor zones that surface regressions before users notice them.
Distribution
Good, borderline, and poor
See the real split of user experiences across every visit — know whether progress is broad or fragile.
Assessment
CWV pass/fail timeline
Track when your site passes or fails Google’s Core Web Vitals assessment — the threshold used for page experience evaluation.
Go deeper
CrUX data is just the starting point
Investigate likely causes with lab data
CrUX tells you what's slow — Lighthouse tells you why. Run a full audit to surface render-blocking resources, layout shifts, and optimization opportunities.
Isolate page-specific issues from site-wide trends
Is this page underperforming, or is the whole site? Compare a URL's CrUX metrics against its origin to separate local regressions from broader problems.
Benchmark against competitors
See how your CrUX Core Web Vitals stack up against up to 4 other sites. Same real-world Chrome data, side by side.
Track over time
Don't just check once — monitor it
Set up alerts to get notified when Core Web Vitals regress, or subscribe to weekly reports that land in your inbox when CrUX data updates.
Frequently Asked Questions
Common questions about Chrome User Experience Report data and how PerfKit helps you analyze real-world performance.
- What is the Chrome User Experience Report (CrUX)?
- The Chrome User Experience Report (CrUX) is a public dataset of real-world user experience data collected from millions of Chrome users who have opted in to sharing usage statistics. It captures Core Web Vitals and other performance metrics for websites, providing field data that reflects how actual users experience the web across different devices and network conditions.
- What are Core Web Vitals?
- Core Web Vitals are a set of three metrics that Google uses to measure real-world user experience: Largest Contentful Paint (LCP) measures loading performance, Interaction to Next Paint (INP) measures interactivity and responsiveness, and Cumulative Layout Shift (CLS) measures visual stability. These metrics are part of Google's page experience signals and can influence search rankings alongside other factors.
- How does this tool differ from PageSpeed Insights?
- While PageSpeed Insights shows current CrUX field data alongside Lighthouse lab results, PerfKit focuses on historical trend analysis. PerfKit visualizes 6 months of P75 data, form-factor breakdowns, and performance score progression — making it easier to spot regressions, validate fixes, and track improvement over time rather than just seeing a point-in-time snapshot. You can also compare multiple URLs side-by-side or benchmark a page against its origin.
- How often is CrUX data updated?
- CrUX data is collected and aggregated on a rolling 28-day basis. The dataset is updated weekly, so the metrics you see represent the 75th percentile (P75) of user experiences over the most recent 28-day collection period.
- What does P75 mean in the context of web performance?
- P75 (75th percentile) means that 75% of user experiences were at or below this value. It is the standard threshold used by Google for Core Web Vitals assessment. For example, an LCP of 2.5s at P75 means that 75% of page loads had an LCP of 2.5 seconds or faster.
- Can I check any website's performance?
- You can check any website that has sufficient traffic in the CrUX dataset. The Chrome User Experience Report requires a minimum number of real user visits to include a site. Very new, low-traffic, or private websites may not have CrUX data available.