Glossary
What is Core Web Vitals?
Core Web Vitals are Google's measures of page experience: how fast the main content loads, how quickly the page responds, and how stable it is.
Updated
Core Web Vitals are three measurements of real-world page experience, which Google uses as a ranking signal.
| Metric | Measures | Good |
|---|---|---|
| Largest Contentful Paint (LCP) | How quickly the main content appears | 2.5 seconds or less |
| Interaction to Next Paint (INP) | How quickly the page responds to clicks and taps | 200 milliseconds or less |
| Cumulative Layout Shift (CLS) | How much the layout jumps while loading | 0.1 or less |
How it matters
They're one signal among many, and a small one compared with relevance and quality. But a slow, jumpy page frustrates readers, which costs you more than rankings.
Improving them
- Compress and properly size images; set their width and height.
- Reduce and defer JavaScript.
- Serve from a fast host or CDN.
- Avoid inserting content above existing content after load.
Measure with PageSpeed Insights, or the Core Web Vitals report in Search Console, which uses real visitors' data.
Related
- Google Search ConsoleGoogle Search Console is Google's free tool that shows how your site performs in search: which queries bring clicks, which pages are indexed, and what's wrong.
- Crawl budgetCrawl budget is how many pages a search engine will crawl on your site in a given time. It only becomes a problem on large sites.