Definition
Core Web Vitals are a set of specific metrics that Google uses to measure real-world user experience on web pages. As of 2026, the three Core Web Vitals are: Largest Contentful Paint (LCP), which measures loading performance — how quickly the main content of a page becomes visible; Interaction to Next Paint (INP), which measures responsiveness — how quickly a page responds to user interactions like clicks or taps; and Cumulative Layout Shift (CLS), which measures visual stability — how much the page layout shifts unexpectedly during loading.
Google considers good scores to be: LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. These thresholds are based on the 75th percentile of page loads, meaning 75% of your visitors should experience scores at or better than these targets. You can check your scores in Google Search Console, PageSpeed Insights, or Chrome DevTools.
Core Web Vitals became a ranking factor in 2021 and their importance has grown since. While content relevance and backlinks still outweigh page experience signals, Core Web Vitals can be a tiebreaker between similarly relevant pages. Sites with poor vitals may also see reduced crawl rates and lower visibility in competitive niches.
Why it matters
Core Web Vitals represent Google's commitment to rewarding fast, stable, and responsive websites. For users, poor vitals mean frustrating experiences — slow loading, unresponsive buttons, and content that jumps around as the page renders. For site owners, poor vitals mean higher bounce rates, lower engagement, and a ranking disadvantage.
Improving Core Web Vitals often requires technical changes (image optimization, lazy loading, efficient JavaScript), but the payoff extends beyond SEO. Faster, more stable pages improve conversion rates, user satisfaction, and overall business performance.