Google introduced Core Web Vitals to quantify what users experience when visiting web pages. Rather than theoretical performance scores, these metrics measure what real users actually encounter.

The Three Core Web Vitals

Largest Contentful Paint (LCP) measures how long it takes for the main content to load. Good LCP is under 2.5 seconds. Interaction to Next Paint (INP) replaced First Input Delay in 2024 and measures how quickly the page responds to user interactions. Good INP is under 200 milliseconds. Cumulative Layout Shift (CLS) measures unexpected layout movements. Good CLS is under 0.1.

Why Core Web Vitals Matter for SEO

Core Web Vitals are confirmed Google ranking factors as part of the page experience signals. While content relevance remains primary, poor Core Web Vitals can hurt rankings, especially in competitive spaces where other factors are equal. Beyond rankings, poor performance directly impacts user behavior and conversion rates.

Measuring Core Web Vitals

Google Search Console shows Core Web Vitals data from real users. PageSpeed Insights provides both lab and field data. Chrome DevTools and Lighthouse offer detailed diagnostics. Field data from real users matters more than lab tests because it reflects actual experience across devices and network conditions.

Improving Core Web Vitals

LCP improves with faster servers, optimized images, and efficient resource loading. INP improves by minimizing JavaScript execution and breaking up long tasks. CLS improves by reserving space for dynamic content and avoiding layout-shifting elements. Each metric requires different optimization strategies.