Core Web Vitals — Definition & Meaning
What is Core Web Vitals?
Core Web Vitals are Google's three page-experience metrics: LCP (loading), INP (interactivity — replaced FID in 2024), and CLS (visual stability). They're a confirmed Google ranking factor, though a small one — a tiebreaker between otherwise-equal pages more than a primary lever.
Key points
- LCP (Largest Contentful Paint): the main content should render within 2.5 seconds. Above 4s = poor.
- INP (Interaction to Next Paint): user interactions should respond within 200ms. Above 500ms = poor.
- CLS (Cumulative Layout Shift): visual stability score should be under 0.1. Above 0.25 = poor.
- Measured on real users via the Chrome UX Report, not your dev laptop — mobile 4G is the benchmark environment.
- The impact on rankings is small vs content quality, but Core Web Vitals dramatically affect CTR, bounce rate, and conversion.
Example
Two competing pages both rank #3 for a query. The one with green Core Web Vitals wins the tiebreaker over the one with red — and also converts 20-40% more of the clicks it earns because users don't bounce.
Frequently asked questions
Are Core Web Vitals a ranking factor?
Yes — but a minor one. Content relevance, backlinks, and topical authority all outweigh CWV. Treat CWV as a tiebreaker and a UX improvement, not a primary ranking lever.
How do I measure my Core Web Vitals?
GSC → Experience → Core Web Vitals shows real-user data. PageSpeed Insights shows lab + field data. Chrome DevTools' Lighthouse tab shows lab data during development.
What replaced First Input Delay (FID)?
INP — Interaction to Next Paint — replaced FID in March 2024. INP is a stricter, whole-interaction latency measurement, whereas FID only measured the first interaction's input delay.