Definition
Google's Core Web Vitals are three measurements of user-perceived page quality: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). They are a confirmed ranking signal and appear in Search Console.
Why it matters
Field Core Web Vitals pass/fail rate is a direct search-rank input. Unlike Lighthouse, which is synthetic, CWV are measured on real users via the Chrome User Experience Report, so a site can have a 98 Lighthouse score and still fail CWV in the field.
How we think about it
We target green across all three vitals on every rebuild. LCP sub-2.5s, INP sub-200ms, CLS under 0.1. Achieved via static generation, aggressive image optimization, and zero layout-jumping scripts above the fold.