What are Core Web Vitals?
Core Web Vitals are three metrics Google uses to measure real-world page experience: Largest Contentful Paint for loading, Interaction to Next Paint for responsiveness and Cumulative Layout Shift for visual stability. They are measured from real Chrome users, and a page passes when 75 percent of visits meet the good thresholds.
The three metrics
Largest Contentful Paint should be 2.5 seconds or less. Interaction to Next Paint should be 200 milliseconds or less. Cumulative Layout Shift should be 0.1 or less. Interaction to Next Paint replaced First Input Delay in March 2024.
Field data and lab data
Search Console and PageSpeed Insights report field data from the Chrome User Experience Report, collected over the previous 28 days. Lighthouse runs a lab test on one simulated device, which is useful for finding problems but is not the data Google uses for search.
Do they affect rankings?
Core Web Vitals are part of Google's page experience signals. Relevance comes first, but between pages of similar quality a faster, steadier page has the edge, and visitors are more likely to stay on it.
