Free Core Web Vitals Lighthouse Test

Run a focused Google Lighthouse Performance audit to measure Largest Contentful Paint, Cumulative Layout Shift, Interaction to Next Paint, and other Core Web Vitals.

Free Tool

Free Core Web Vitals Lighthouse Test

LCP, CLS, and INP are Google's three primary page experience ranking signals. Our free Lighthouse test measures all three against Google's published thresholds and tells you exactly what to fix.

Free Core Web Vitals Threshold Guide

LCP
Largest Contentful Paint

Measures how long it takes for the largest visible content element (image, video, or text block) to fully render.

Good
≤ 2.5s
Needs Improvement
2.5s – 4.0s
Poor
> 4.0s
CLS
Cumulative Layout Shift

Measures visual stability — how much page elements unexpectedly move during load. Caused by images without dimensions, ad slots, and dynamic injections.

Good
≤ 0.1
Needs Improvement
0.1 – 0.25
Poor
> 0.25
INP
Interaction to Next Paint

Measures the responsiveness of your page to user interactions — how quickly the page visually responds after clicks, taps, and keyboard input.

Good
≤ 200ms
Needs Improvement
200ms – 500ms
Poor
> 500ms

Free CWV Optimization Tools