What are Core Web Vitals?
Core Web Vitals are three scores that measure loading, responsiveness and visual stability. Together they describe whether your site feels quick and reliable to use.
They come from Google and are documented on web.dev. Unlike a simple “speed score”, they are based on what real visitors experience on real phones and computers. That matters for a small business, because most of your customers will find you on a mobile, often on a patchy 4G signal outside a shop or on a building site.
What are the 2026 thresholds?
The targets have not changed since INP replaced First Input Delay (FID) on 12 March 2024. To pass, a page needs a “good” result on all three.
| Metric | What it measures | Good | Needs improvement | Poor |
|---|---|---|---|---|
| LCP: Largest Contentful Paint | How long the main content (usually a big image or heading) takes to appear | 2.5 seconds or less | 2.5 to 4 seconds | Over 4 seconds |
| INP: Interaction to Next Paint | How quickly the page responds when someone taps or clicks | 200 milliseconds or less | 200 to 500 milliseconds | Over 500 milliseconds |
| CLS: Cumulative Layout Shift | How much the page jumps around while loading | 0.1 or less | 0.1 to 0.25 | Over 0.25 |
Google measures these at the 75th percentile, split by mobile and desktop. In plain terms, at least three out of four visits need to hit the “good” target for the page to pass. The date INP took over is confirmed in Google’s web.dev announcement.
Do Core Web Vitals affect your Google rankings?
They play a part, but a small one. Relevance and helpful content come first.
Google says Core Web Vitals, along with other page experience signals, align with what its core ranking systems seek to reward, and it highly recommends achieving good scores (Google Search Central: Core Web Vitals). It also says Search “always seeks to show the most relevant content, even if the page experience is sub-par” (Google page experience guidance).
So a slow site with excellent content can still rank, and a fast site with thin content will not. Where speed really earns its keep is with customers. A page that loads slowly or jumps about as someone tries to tap “Call now” loses enquiries, whether they came from local SEO or paid Google Ads.
Is a slow website costing you enquiries?
We build fast, mobile-first websites for UK small businesses and fix speed problems on existing sites.
How do you check your Core Web Vitals?
Two free Google tools give you everything you need. You do not need to be technical to read them.
- PageSpeed Insights (pagespeed.web.dev): paste in any URL. The top section shows real-visitor data if Google has enough, and the lower section shows a lab test with suggestions.
- Search Console: the Core Web Vitals report groups your pages into Good, Needs improvement and Poor, for mobile and desktop.
- Chrome DevTools: useful for developers who want to see exactly which element is slow.
A quick note on the two types of data. Field data comes from real Chrome users over the past 28 days. Lab data is a one-off simulated test. Field data is what Google uses; lab data is handy for diagnosing problems. Small sites often lack enough visitors for field data, in which case the lab results are your best guide.
What usually slows down a small business website?
On most small business sites the same few culprits come up again and again. The good news is that most are fixable without a rebuild.
- Huge images. A 5MB photo straight off a phone is a common cause of poor LCP. Resize and compress images, and use modern formats such as WebP.
- Too many plugins or apps. Each one can add scripts that slow responses and hurt INP.
- Third-party scripts. Chat widgets, review carousels, booking tools and tracking tags all add weight.
- Images and adverts without set sizes. The page reserves no space, then jumps when they load, which hurts CLS.
- Cookie banners and pop-ups that push content down after the page appears.
- Cheap or overloaded hosting, which slows the very first response from the server.
What should you fix first?
Fix whatever affects your most important pages: usually the homepage, your main service pages and your contact page. Work through this checklist in order.
- Run your homepage and top service page through PageSpeed Insights on mobile.
- Note which of the three metrics fail.
- For poor LCP, compress the main hero image and check your hosting.
- For poor INP, remove plugins and widgets you no longer use.
- For poor CLS, make sure every image and embed has a width and height set.
- Retest, then check Search Console over the following weeks, as field data takes time to update.
If your site is old or built on a heavy theme, a rebuild can be more cost-effective than patching. Our guide to website costs in the UK helps you weigh it up. Speed is also part of being easy for AI tools to read, which we cover in our AI search engines guide.
FAQs
What is a good Core Web Vitals score?
A good result is 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.
Did INP replace FID?
Yes. Interaction to Next Paint replaced First Input Delay as a Core Web Vital on 12 March 2024.
Is PageSpeed Insights the same as Core Web Vitals?
Not quite. PageSpeed Insights shows Core Web Vitals from real visitors when available, plus a separate lab performance score. The real-visitor figures are the ones Google uses.
Will fixing Core Web Vitals get me to the top of Google?
Not on its own. Google puts relevance and helpful content first, but good page experience can help when competing pages are similarly useful, and it helps visitors turn into enquiries.
Why does Search Console say there is not enough data?
Core Web Vitals field data needs a minimum amount of real Chrome traffic. Smaller sites often fall below it, so use PageSpeed Insights lab results as a guide instead.
