Core Web Vitals Reference

🖼️

LCP Largest Contentful Paint

Measures loading performance. Marks when the largest image or text block becomes visible in the viewport.

✅ Good≤ 2.5s

⚠️ Needs Work2.5s – 4.0s

❌ Poor> 4.0s

🖱️

Measures responsiveness. Assesses overall responsiveness to user interactions (replaced FID in March 2024).

✅ Good≤ 200ms

⚠️ Needs Work200ms – 500ms

❌ Poor> 500ms

📐

Measures visual stability. Quantifies unexpected layout shifts during the entire lifespan of a page.

✅ Good≤ 0.1

⚠️ Needs Work0.1 – 0.25

❌ Poor> 0.25

Time until first text or image is painted. Good: ≤ 1.8s · Needs Work: 1.8s–3s · Poor: >3s

Server response time. Good: ≤ 800ms · Needs Work: 800ms–1.8s · Poor: >1.8s

Lab proxy for INP. Sum of blocking time over 50ms. Good: ≤ 200ms · Poor: >600ms

Pages must be usable on mobile. Test with Google's Mobile-Friendly Test tool.

Secure connection is a confirmed lightweight ranking signal since 2014.

Popups that block content on mobile can result in ranking demotion.

Improve LCPPreload hero images, use a CDN, optimize server response times, remove render-blocking resources.

Improve INPBreak up long JavaScript tasks, use web workers, defer non-critical JS, avoid heavy event listeners.

Improve CLSAlways set width & height on images/videos, avoid injecting content above existing content, use CSS transform for animations.

MeasureUse PageSpeed Insights, Chrome DevTools, CrUX dashboard, or Search Console's Core Web Vitals report.