Core Web Vitals Checker
Measures Core Web Vitals (LCP, INP, CLS) of any URL via Google's PageSpeed Insights API. Mobile vs desktop choice. Verdict per official threshold.
URL to measure
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Frequently asked questions
Which Core Web Vitals are measured? +
LCP (Largest Contentful Paint, ≤ 2.5s = good), INP (Interaction to Next Paint, ≤ 200ms = good), CLS (Cumulative Layout Shift, ≤ 0.1 = good) — the 3 official Google signals. Bonus: TBT, FCP, Speed Index. The 0-100 Lighthouse score synthesizes everything.
Why does the score sometimes differ from my own measurements? +
PageSpeed Insights uses a controlled environment (emulated Moto G4, 4G throttling). Your real measurements in Chrome depend on your device and network. The Core Web Vitals Google uses for ranking come from the CrUX dataset (real user data) — not the Lighthouse lab. PSI shows both: lab is faster to iterate, field is more representative.
What's the real SEO impact? +
Small but real. On competitive KWs where technical pages are already optimized, CWV breaks the tie. On long-tail KWs where no page has optimized, it's secondary. The bulk of equity comes from backlink authority + content. Aim green on all 3 CWVs before worrying about the global Lighthouse score.
Green CWV but still not on page 1?
CWVs decide at the margin. To really climb, you need external authority — targeted editorial backlinks from the Stringer network.