Free tool

Core Web Vitals checker

See how real Chrome users experience any website: INP, LCP and CLS at the 75th percentile over the last 28 days, straight from Google's Chrome UX Report. No sign-up.

Core Web Vitals of popular sites

Real-user results for 132 sites, from the Chrome UX Report.

Developer tools

Hosting and cloud

Frameworks and docs

Productivity and collaboration

Design

Payments and business

AI

Media and community

E-commerce

What the Core Web Vitals measure

Google rates a page by the 75th percentile of real visits: 3 in 4 visitors must get a good experience for a metric to count as good. A site passes the assessment when LCP, CLS and INP are all good.

Interaction to Next Paint (INP): How quickly the page responds to clicks, taps and key presses. Good at or under 200 ms, poor above 500 ms.
Largest Contentful Paint (LCP): How long the main content takes to appear. Good at or under 2.5 s, poor above 4.0 s.
Cumulative Layout Shift (CLS): How much the layout jumps around while the page loads. Good at or under 0.10, poor above 0.25.

Real-user data tells you after the fact

The Chrome UX Report averages 28 days of visits, so a slow release shows up here weeks after it shipped. Vitalgate runs Lighthouse on every pull request and fails the check when a change breaks your budgets, before it reaches your users.