Tools
Core Web Vitals Checker
Analyse the Core Web Vitals of a webpage. View LCP, CLS and INP for both mobile and desktop, including real user data.
Analyse a page
Enter a URL to analyse the Core Web Vitals. The analysis takes 10–20 seconds.
Why this matters
What are Core Web Vitals and why are they important?
Core Web Vitals are three metrics Google uses to assess the user experience of a page. They are an official ranking factor within the Page Experience signal.
LCP - Largest Contentful Paint
Measures how quickly the largest visible element (image, heading, block) loads. Good: under 2.5 seconds. Poor LCP is often caused by slow servers, large images, or render-blocking resources.
INP / TBT - Interactivity
Interaction to Next Paint measures how quickly the page responds to clicks and taps. In lab data, Total Blocking Time is used as a proxy. Good: under 200ms TBT / 200ms INP. Large JavaScript bundles are the main cause of poor scores.
CLS - Cumulative Layout Shift
Measures unexpected layout shifts during loading. Good: under 0.10. Images without fixed dimensions, late-loading ads and fonts that change size are common causes.
Lab vs. real data
Lighthouse simulates a slow connection in a controlled environment. CrUX data comes from real Chrome users and is more reliable for SEO purposes. When both are available, focus primarily on the real user data.
Google's Page Experience signal
Since 2021, Google has used Core Web Vitals as a ranking factor within the Page Experience signal. While content quality carries more weight, a poorly performing page can fall behind competitors with similar content. For e-commerce and news sites - where speed directly impacts conversion - optimisation is especially worthwhile.
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We help you with speed optimisation
Core Web Vitals are just one part of web performance. We audit your full website and deliver measurable improvements in load time, interactivity and stability.