The three metrics
- Largest Contentful Paint (LCP): the time until the biggest thing in the first screen, usually a hero image or headline, is drawn. Good: 2.5 s or less. Needs work: up to 4 s. Poor: over 4 s. Slow LCP is almost always big images, slow servers or code that blocks rendering.
- Interaction to Next Paint (INP): how long the page takes to visibly respond after you tap or type, measured across the whole visit. Good: 200 ms or less. Poor: over 500 ms. Caused by heavy JavaScript (builders, trackers, chat widgets). INP replaced First Input Delay in March 2024.
- Cumulative Layout Shift (CLS): how much content moves after it first appears, like a button that jumps as an ad or image loads above it. Good: 0.1 or less. Poor: over 0.25. Caused by images without set dimensions, late-loading fonts and injected banners.
A page passes when it meets all three at the 75th percentile of visits, meaning three quarters of real visitors had a good experience.
Where to see yours
Google Search Console has a Core Web Vitals report that groups your pages into good, needs improvement and poor, using data from real Chrome users over the past 28 days. PageSpeed Insights shows the same field data for a single page plus a lab test with suggested fixes. Small sites may show 'not enough data' in the field section because too few visitors use Chrome; the lab numbers still tell you what to fix.
How much do they matter?
For ranking, they are a minor factor compared to the relevance and quality of the content; a slow page with the best answer still outranks a fast page with a weak one. For visitors, they matter a great deal, because they measure the frustration that makes people leave. Treat passing all three as table stakes for a business site rather than as an SEO trick. How fast a website should load covers the business case, and the slow website page covers the fixes.