Free page speed & Core Web Vitals test
Google ranks on how fast your pages feel. Enter a URL for mobile & desktop Lighthouse scores, every Core Web Vital — LCP, CLS, INP, TBT — and real-user field data, with the metrics to fix first.
Every Core Web Vital, lab and real-user
Loading — LCP
- Largest Contentful Paint
- First Contentful Paint
- Speed Index
- Good ≤ 2.5s
Interactivity — INP / TBT
- Interaction to Next Paint
- Total Blocking Time
- Time to Interactive
- Good INP ≤ 200ms
Stability — CLS
- Cumulative Layout Shift
- Visual jank while loading
- Good ≤ 0.1
- Poor > 0.25
Lab + field
- Mobile & desktop Lighthouse
- Real-user CrUX data
- Per-metric ratings
- 0-100 score
Page speed questions, answered
What are Core Web Vitals?
Three Google-defined metrics for real-world page experience: LCP (loading — when the main content appears), INP (interactivity — how fast the page responds to input), and CLS (visual stability — how much the layout shifts). Google uses them as a ranking signal, so slow vitals can cost you search positions.
What's the difference between lab and field data?
Lab data is a synthetic Lighthouse run on a simulated device — repeatable and available for any URL. Field data comes from the Chrome UX Report (CrUX): real Chrome users' measurements over the last 28 days. Field data is what Google actually ranks on, but it only exists once a page has enough traffic.
What's a good page speed score?
Google's Lighthouse performance score runs 0-100: 90+ is good (green), 50-89 needs improvement, under 50 is poor. But the score is a summary — fix the individual Core Web Vitals (LCP, INP, CLS) that fall outside their good thresholds, since those are what affect ranking and users.
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