Core Web Vitals Checker
Real-user Core Web Vitals (CrUX) plus a Lighthouse lab test — clearly separated.
Free. No account needed. We analyze the page you enter and show only what we actually measured.
Field data vs lab data — and why we show both
Core Web Vitals measure what visitors actually experience: loading (LCP), responsiveness (INP), and visual stability (CLS). This tool shows two views and never mixes them: field data — Google's Chrome UX Report, the 75th percentile of real visitors over the last 28 days — and a fresh Lighthouse lab test run at the moment you click.
Field data is what Google's ranking systems use, but it only exists for URLs with enough real traffic. When it's missing we say so plainly and show the lab results — a simulated test that's great for debugging but not the same thing as real-user experience. Every category label (good / needs improvement / poor) is Google's own threshold; we don't invent composite scores.
Because each test costs real Google API quota, runs are capped per visitor per day and results are cached for 24 hours. A repeat check of the same URL is instant and free.