A slow website quietly costs money. Visitors leave before the page appears, forms feel broken when buttons lag, and layouts that jump around cause mis-taps on phones. Google measures these experiences with a set of metrics called Core Web Vitals. You do not need to be a developer to understand them, and you do not need a perfect score to benefit from improving them.
The three Core Web Vitals
Google's Core Web Vitals measure loading, responsiveness and visual stability, based on how real visitors experience your pages.
| Metric | What it measures | Good | Needs improvement | Poor |
|---|---|---|---|---|
| Largest Contentful Paint (LCP) | How long the main content takes to appear | 2.5 seconds or less | Up to 4 seconds | Over 4 seconds |
| Interaction to Next Paint (INP) | How quickly the page responds to taps, clicks and typing | 200 milliseconds or less | Up to 500 milliseconds | Over 500 milliseconds |
| Cumulative Layout Shift (CLS) | How much the layout jumps while loading | 0.1 or less | Up to 0.25 | Over 0.25 |
Google evaluates each metric at the 75th percentile of real page visits, split by mobile and desktop. In plain terms, at least three out of four visits should have a good experience.
INP replaced the older First Input Delay (FID) metric as a Core Web Vital in March 2024. If an old audit mentions FID, it is out of date.
Do Core Web Vitals affect Google rankings?
Google says its ranking systems reward pages that offer a good page experience, and Core Web Vitals are part of that. Google is also clear that relevance comes first: a fast page with thin content will not outrank a genuinely helpful one. Think of speed as a tie-breaker and a conversion booster, not a shortcut to the top.
The bigger payoff is usually with your customers. A page that loads quickly and responds instantly simply gets more calls, bookings and form submissions.
How to check your website for free
- PageSpeed Insights (pagespeed.web.dev). Enter a URL to see real-user data when Google has enough of it, plus lab tests and specific recommendations.
- Google Search Console. The Core Web Vitals report groups your URLs into good, needs improvement and poor for mobile and desktop.
- Your own phone on mobile data. Open your homepage and a key service page away from office Wi-Fi. If you get impatient, your customers do too.
Lab tests are useful for diagnosing problems, but the field data from real visitors is what Google uses for Core Web Vitals.
The fixes that usually matter most
For slow loading (LCP)
- Resize and compress images. Serve modern formats such as WebP or AVIF at the size they are displayed. Oversized hero images are the most common cause of slow LCP on small business sites.
- Do not lazy-load the main image. The hero image should load immediately; lazy-load images further down the page.
- Use good hosting and a CDN. Slow server response delays everything that follows.
- Limit render-blocking files. Large style sheets, fonts and scripts loaded in the page head hold back the first paint.
For slow responses (INP)
- Cut third-party scripts. Chat widgets, heatmaps, multiple tracking tags and social embeds all compete for the browser's attention. Remove anything you are not actively using.
- Load non-essential scripts later. Defer tools that are not needed for the first interaction.
- Keep page builders lean. Heavy themes and stacked plugins often add large amounts of JavaScript.
For jumping layouts (CLS)
- Set image and video dimensions so the browser reserves space before they load.
- Reserve space for banners, ads and embeds instead of letting them push content down.
- Load web fonts carefully to avoid large text reflows.
A 30-minute speed checklist
- Run your homepage and top service page through PageSpeed Insights on mobile.
- List every third-party script on the site and remove the ones nobody uses.
- Check the file size of your hero images; most should be well under 200 KB.
- Confirm images have width and height set.
- Re-test after changes and check Search Console again after a few weeks of new data.
When to rebuild instead of patching
If a site is built on a heavy theme with dozens of plugins, fixes can feel like whack-a-mole. A lean rebuild is often faster and cheaper over time, especially if the site also needs better content and conversion paths. Our guide to small business website costs explains what to expect.
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Frequently Asked Questions
What are good Core Web Vitals scores?
Google considers a page good when Largest Contentful Paint is 2.5 seconds or less, Interaction to Next Paint is 200 milliseconds or less and Cumulative Layout Shift is 0.1 or less, measured at the 75th percentile of real visits.
What replaced First Input Delay?
Interaction to Next Paint (INP) replaced First Input Delay as a Core Web Vital in March 2024. INP measures responsiveness across all interactions on a page, not just the first one.
Does website speed affect SEO?
Page experience, including Core Web Vitals, is used by Google's ranking systems, but relevance and helpful content matter more. Speed works best as a tie-breaker and has a direct effect on conversions.
How do I check my website speed?
Use Google PageSpeed Insights for page-level tests and recommendations, and the Core Web Vitals report in Google Search Console to see how groups of pages perform for real visitors.
What slows down small business websites the most?
The most common causes are oversized images, too many third-party scripts such as chat and tracking tools, heavy themes and plugins, and slow hosting.
