🚀 Free tool · no signup, no paid API key

Core Web Vitals Checker

Run a live Lighthouse audit on any URL and get a performance score plus LCP, CLS, and INP.

What This Tool Does

Core Web Vitals are Google's standardized measurements of real page experience: how fast the main content appears (LCP), how much the layout jumps around while loading (CLS), and how responsive the page feels to an actual click or tap (INP).

This tool runs Google's own PageSpeed Insights API (Lighthouse) against any URL you give it and returns the performance score plus each of these metrics, for either mobile or desktop.

Why It Matters

  • Core Web Vitals are a confirmed Google ranking signal — not the biggest one, but a real tie-breaker between otherwise-similar pages.
  • Poor Web Vitals cost conversions independently of rankings: slow, jumpy pages measurably lose visitors before they ever act.
  • Lab data (what this tool measures) can miss what real visitors experience — when field data (real-user CrUX data) is available for a URL, this tool shows that too, so you're not flying blind on lab numbers alone.

How to Use It

  1. Paste the full URL you want to test.
  2. Choose Mobile or Desktop — Google evaluates and ranks these separately, and mobile is usually the stricter test.
  3. Click Run Check and wait — a real Lighthouse run takes 15-30 seconds, that's normal, not a bug.
  4. Read the score and each metric; anything flagged in the lab-only note means no real-user data exists yet for that URL, so treat the lab numbers as an estimate.
Lighthouse runs live against the URL, so this can take 15-30 seconds — that's normal.

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