Core Web Vitals Monitoring
Lab + Field Data, Every Test
We integrate directly with Google PageSpeed Insights. Each test returns lab metrics (Lighthouse) and, when Google publishes field data for your URL, real-user CrUX numbers. You see LCP, INP, CLS, FCP, TBT and Speed Index with full historical tracking, so you compare trends instead of one-off snapshots.
Why it matters
Direct PSI integration, stored test history, mobile and desktop strategies per page
Native Google PSI Integration
Direct API integration. No proxies, no workarounds.
Track LCP, INP, CLS history
Store every test result. See how metrics change over 30, 90, or 365 days.
Compare Mobile vs Desktop
Run mobile and desktop on each monitored page. Most sites diverge by device; you see both without switching tools.
Lab + Field Data in Every Result
PageSpeed Insights returns two kinds of data:
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Lab data: Simulated Lighthouse runs in a controlled environment. Consistent and repeatable.
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Field data (CrUX): Real-user metrics from Chrome. Shown only when the URL has enough traffic for Google to publish CrUX.
We show both in every result. When CrUX is present, you get real-user numbers; when it is not, lab data still gives a stable baseline to work from.
Both shown when CrUX is available; lab-only otherwise.
The Metrics We Track
| Metric | What It Measures |
|---|---|
| LCP | Largest Contentful Paint |
| INP | Interaction to Next Paint |
| CLS | Cumulative Layout Shift |
| FCP | First Contentful Paint |
| TBT | Total Blocking Time |
| Speed Index | Visual completeness over time |
Both strategies run for every monitored page.
Mobile vs Desktop
Core Web Vitals diverge by device. Mobile is often slower (networks and hardware). We run mobile and desktop tests on every page you monitor, so a strong desktop score cannot hide a weak mobile result.
See also