What are the three Core Web Vitals?

The three Core Web Vitals are LCP (Largest Contentful Paint) — how long the largest visible element takes to load, target under 2.5 seconds; CLS (Cumulative Layout Shift) — how much the layout moves while loading, target under 0.1; and INP (Interaction to Next Paint) — how quickly the page responds to user input, target under 200 milliseconds.

Do Core Web Vitals directly affect Google rankings?

Yes. Google confirmed Core Web Vitals as ranking signals in 2021 as part of the Page Experience update. However, content quality and relevance remain the strongest ranking factors. Poor Core Web Vitals scores will not prevent a page from ranking if it has significantly better content than competing pages — but between two otherwise equal pages, better Core Web Vitals wins.

How do I check my Core Web Vitals scores?

Run the Core Web Vitals Checker in the AIWebPageSEO Audit Tools. It pulls real field data from Google's Chrome User Experience Report (CrUX) where available, supplemented by lab data from Lighthouse. Field data reflects real user experience across all devices and connections — it is the data Google actually uses for ranking decisions.

Core Web Vitals: LCP, CLS and INP Explained and Fixed

Core Web Vitals are Google's page experience metrics — LCP, CLS and INP. They measure how fast your page loads, how stable the layout is, and how responsive it is to user input. All three are direct Google ranking factors.

⚡ Check Core Web Vitals All Audit Tools →

Field data vs lab data — which matters for rankings?

Google uses field data — real measurements from actual Chrome users visiting your pages — for ranking decisions. Lab data, from tools like Lighthouse running in a controlled environment, is useful for diagnosis but does not directly affect rankings. If your site has enough traffic, the Core Web Vitals Checker pulls real field data from the Chrome User Experience Report.

Important: New pages with low traffic may not have field data. In this case Google uses lab data as a proxy. This means new pages are more sensitive to lab score improvements than established high-traffic pages.

The fastest fixes for each Core Web Vital

LCP — Largest Contentful Paint

Compress and convert your hero image to WebP format
Add loading="eager" and fetchpriority="high" to the LCP image element
Preconnect to your image CDN or font provider
Upgrade to faster hosting if TTFB is over 600ms

CLS — Cumulative Layout Shift

Add explicit width and height attributes to every image
Reserve space for ad slots with min-height even before ads load
Use font-display: optional to prevent font swap layout shift

INP — Interaction to Next Paint

Break up long JavaScript tasks into smaller chunks
Defer non-critical JavaScript with defer or async
Reduce third-party script impact — each analytics and marketing tag adds to INP

⚡ Check Core Web Vitals Now

Run the Core Web Vitals Checker and get actionable results in minutes. Pay as you go — no subscription needed.

Check Core Web Vitals →

Core Web Vitals: LCP, CLS and INP Explained and Fixed

Field data vs lab data — which matters for rankings?

The fastest fixes for each Core Web Vital

LCP — Largest Contentful Paint

CLS — Cumulative Layout Shift

INP — Interaction to Next Paint

⚡ Check Core Web Vitals Now

Related tools