Web design
Core Web Vitals in Plain English
Core Web Vitals are Google's three measures of how a page feels to use. Here is what they mean, the targets, how to check your site and what to fix first.
On this page
If you have run a speed test on your website, you have probably seen the words LCP, INP and CLS. They are the three parts of Core Web Vitals, Google’s way of measuring how a page feels to use.
This guide explains each one without the jargon, gives the official targets and shows how to check your own site. It builds on our post about whether website speed affects SEO.
What are they?
They are three measurements of real visitors’ experience of a page: how quickly the main content appears, how quickly the page responds when you tap or click, and whether things jump around while it loads. Google’s Search Central page describes them as part of page experience and says it highly recommends site owners achieve good scores for success with Search.
The three measures
| Measure | In plain English | Good target |
|---|---|---|
| LCP (Largest Contentful Paint) | How long until the biggest thing on screen, such as a main image or heading, has appeared | 2.5 seconds or less |
| INP (Interaction to Next Paint) | How quickly the page reacts when someone taps a button or opens a menu | 200 milliseconds or less |
| CLS (Cumulative Layout Shift) | How much the page jumps about while it loads, such as a button moving as you go to tap it | 0.1 or less |
These targets are from Google’s web.dev guidance. A page counts as good when it meets all three for at least 75% of visits.
Do they affect rankings?
Google says these measures align with what its core ranking systems seek to reward. It does not describe a specific boost, and it does not say good scores guarantee a place in the results. Treat them as one part of a site that is pleasant to use, not a trick. A fast page that says nothing useful will not rank, and a useful page that is painfully slow loses visitors.
How to check yours
- PageSpeed Insights is Google’s free tool. Paste in an address and it shows the results, with data from real visitors where there is enough.
- Search Console has a Core Web Vitals report, which Google recommends checking, showing how groups of your pages perform. Our Search Console guide covers getting set up.
- Test on a phone. Most people visit on mobile, so judge it there.
New or quiet sites may not have enough real visitor data to show a result. That is normal, not a fault.
Common causes and fixes
These are general patterns, not a guarantee for any one site:
- Slow LCP: large uncompressed images, slow hosting or a heavy slider at the top of the page. Resize and compress images, and keep the top of the page simple.
- Poor INP: too many scripts, such as chat widgets, trackers and pop-ups, competing for attention. Remove what you do not use.
- Layout shift: images without set dimensions, late-loading banners or fonts. Reserve space for them so the page does not jump.
Fix the biggest problem first, then measure again.
What this means for a local business
You do not need perfect scores. You need a site that loads quickly on a phone, responds when tapped and does not jump around while someone is trying to call you or fill in a form. If your site was built on a slow theme or is full of plugins, a rebuild can be cheaper than patching. See our web design service.
Want your site checked?
We build fast, clear websites for UK businesses and can tell you what is slowing yours down. Take a look at our web design service, or try our free website check.
Targets checked against web.dev’s Core Web Vitals page (updated 31 October 2024) and Google Search Central on 14 October 2026. Google changes its guidance, so check those pages if something looks different.
Frequently asked questions
What are the three measures?
Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and Cumulative Layout Shift (visual stability).
What is a good score?
Google’s targets are LCP of 2.5 seconds or less, INP of 200 milliseconds or less and CLS of 0.1 or less, measured at the 75th percentile of visits.
Where can I see my results?
In PageSpeed Insights and in the Core Web Vitals report in Google Search Console.
Will fixing them make me rank first?
No. Google does not promise that. They are one part of page experience alongside useful content.
Do I need to fix everything before my site can rank?
No. Google describes good scores as something to aim for, not a gate. Start with the biggest problem on your most important pages.
