Core Web Vitals Explained for Beginners: LCP, INP and CLS

Core Web Vitals are three measurements Google uses to judge how a page feels to real visitors: how fast the main content appears, how quickly the page responds when you tap something, and whether the layout jumps around while loading. They are part of Google's page experience signals, and more importantly, they reflect whether visitors stay or leave.

The three Core Web Vitals

LCP — Largest Contentful Paint

How long until the biggest visible element (usually the main image or heading block) appears. Good: 2.5 seconds or less.

INP — Interaction to Next Paint

How quickly the page responds visually after a tap, click or key press, measured across the visit. INP replaced FID in March 2024. Good: 200 milliseconds or less.

CLS — Cumulative Layout Shift

How much the page layout jumps while loading — the annoying moment when a button moves just as you tap it. Good: 0.1 or less.

Google assesses these at the 75th percentile of real visits, so most of your visitors need a good experience, not just you on fast Wi-Fi.

How much they affect rankings

Core Web Vitals are a ranking signal, but a modest one. Relevance and content quality matter much more. A slow page with the best answer can still rank. But when pages are otherwise similar, a better experience can help — and a fast page keeps more visitors, which matters for sales either way.

How to check your scores for free

• Search Console → Core Web Vitals report shows real-user data grouped by page type, once your site has enough traffic.
• PageSpeed Insights shows real-user data (when available) and a lab test for any URL.
• The free site audit report shows page weight and fetch time, which are often the root of slow loading.

Fixes that help most

Improve LCP

• Compress and resize the main image; use modern formats like WebP.
• Do not lazy-load the main image at the top of the page.
• Use good hosting and caching so the server responds quickly.
• Reduce heavy scripts and fonts that load before the content.

Improve INP

• Remove unnecessary third-party scripts: chat widgets, trackers, sliders.
• Defer non-essential JavaScript.

Improve CLS

• Always set width and height on images and videos.
• Reserve space for ads and embeds.
• Avoid inserting banners above content after the page loads.

Image weight is the most common problem on small sites. Check your images load correctly with the image URL checker, and write good descriptions while you are there — see image alt text best practices.

A simple order of work

1. Start with mobile, where most visitors are and scores are usually worse.
2. Fix the biggest image on your most visited pages first.
3. Remove one or two third-party scripts you do not truly need.
4. Add width and height to every image and embed.
5. Recheck after 28 days — real-user data in Search Console updates gradually.

Small sites often reach "good" on all three metrics with just these steps.

Related guides

• Noindex vs Disallow in Robots.txt: Which One Should You Use?
• How to Check If a Page Is Indexed by Google (4 Free Ways)
• Crawled – Currently Not Indexed: What It Means and How to Fix It

More free tools: browse all our free SEO tools, no sign-up needed.

Frequently asked questions