Core Web Vitals in 2026: LCP, INP, and CLS

Core Web Vitals are the three user-experience metrics Google uses as a ranking signal. They're worth understanding because a page only "passes" when all three are in the good range.

The three metrics

• LCP — Largest Contentful Paint (loading). When the biggest element in the viewport finishes rendering. Good ≤ 2.5s, poor > 4s.
• INP — Interaction to Next Paint (responsiveness). How quickly the page responds to user input, across the whole visit. Good ≤ 200ms, poor > 500ms.
• CLS — Cumulative Layout Shift (stability). How much visible content unexpectedly moves. Good ≤ 0.1, poor > 0.25.

Anything between good and poor is "needs improvement."

INP replaced FID

In 2024, INP replaced First Input Delay as a Core Web Vital. FID only measured the delay before the first interaction; INP looks at responsiveness across all interactions, which better reflects how the page actually feels.

The pass/fail rule

Google's assessment is strict: the page is "good" only when LCP, INP, and CLS are all in the good band. One poor metric drags the whole verdict down — so fix your worst metric first.

Field vs lab data

• Field data (Search Console, the CrUX report) is what Google uses for ranking — real users, real devices.
• Lab data (Lighthouse, PageSpeed Insights) is a controlled test, useful for debugging but not identical to field results (notably, CLS and INP behave differently in the lab).

Check your numbers

Grab your LCP, INP, and CLS from Search Console or Lighthouse and drop them into the Web Vitals Calculator to see each metric's rating and the overall pass/fail verdict — without memorizing the thresholds.