Awesome Toolkit

Core Web Vitals Reference

Interactive reference for LCP, CLS, INP, FID, FCP, and TTFB — thresholds, diagnosis tips, and fix priorities at a glance.

LCP — Largest Contentful Paint
Measures loading performance. Time for the largest visible element to render.
Good < 2.5s Needs improvement 2.5–4s Poor > 4s
INP — Interaction to Next Paint
Measures interactivity. Responsiveness to user interactions (click, tap, keypress).
Good < 200ms Needs improvement 200–500ms Poor > 500ms
CLS — Cumulative Layout Shift
Measures visual stability. Unexpected layout shifts during page load.
Good < 0.1 Needs improvement 0.1–0.25 Poor > 0.25

About Core Web Vitals

Core Web Vitals are Google's page experience metrics used as ranking signals since 2021. LCP: optimize images (WebP, lazy-load, preload hero), reduce server response time. INP: reduce JavaScript execution time, break up long tasks. CLS: always set width/height on images and embeds, avoid injecting content above existing content. Find your scores via PageSpeed Insights or Chrome DevTools Lighthouse.