To run a Core Web Vitals test for free, enter your URL into Google PageSpeed Insights or our free website speed test and check three metrics: Largest Contentful Paint (LCP), Interaction to Next Paint (INP) and Cumulative Layout Shift (CLS). For a real-visitor view of your whole site, also use the Core Web Vitals report in Google Search Console.
Key takeaways
- Core Web Vitals are LCP, INP and CLS. INP replaced First Input Delay in March 2024.
- Good scores are LCP of 2.5 seconds or less, INP of 200 milliseconds or less and CLS of 0.1 or less (Google, web.dev).
- A page passes when these are met at the 75th percentile of real visits.
- Lab tests help you find problems. Field data shows what real visitors experienced.
What are Core Web Vitals?
Core Web Vitals are three metrics Google uses to measure real-world page experience. They cover loading speed, responsiveness and visual stability.
| Metric | Good | Needs improvement | Poor |
|---|---|---|---|
| LCP | 2.5 s or less | 2.5 to 4 s | Over 4 s |
| INP | 200 ms or less | 200 to 500 ms | Over 500 ms |
| CLS | 0.1 or less | 0.1 to 0.25 | Over 0.25 |
How do you test Core Web Vitals for free?
You can test Core Web Vitals with several free tools, and each shows a different view of your site.
- Our free speed test: enter a URL in our free page speed checker for a quick lab check.
- Google PageSpeed Insights: shows lab results and, when enough data exists, field data from real Chrome users.
- Google Search Console: the Core Web Vitals report groups your URLs by status using real-user data. You must have your site verified.
- Chrome DevTools: run Lighthouse or the Performance panel on your own computer to debug a page.
What is the difference between lab data and field data?
Lab data comes from a simulated test and is useful for finding and fixing issues. Field data comes from real Chrome users over the previous 28 days and shows what visitors actually experienced. The Core Web Vitals assessment uses field data, so a green lab score does not always mean you pass. Read more in our guide on PageSpeed Insights accuracy.
How do you fix failing Core Web Vitals?
- Slow LCP: compress and prioritize the main image, use caching and reduce server response time. See how to fix LCP in WordPress.
- Poor INP: reduce heavy JavaScript and long tasks, and remove scripts you do not need.
- High CLS: set width and height on images and embeds, and reserve space for ads and banners.
For the full list, read our guide on how to improve website speed.
Do Core Web Vitals affect SEO?
Yes, as part of Google’s page experience signals, but they are one factor among many. Relevant, helpful content still matters most. Core Web Vitals are best treated as a way to improve the experience for your visitors.
Frequently asked questions
What replaced First Input Delay?
Interaction to Next Paint (INP) replaced First Input Delay as a Core Web Vital in March 2024.
What is a good Core Web Vitals score?
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.
Why does Search Console show no Core Web Vitals data?
The report needs enough real-user visits to your pages. New or low-traffic sites may not have enough data yet.
Can I test Core Web Vitals on a page that is not public?
Yes, with Lighthouse in Chrome DevTools. It gives lab results only, not field data.
How often should I check Core Web Vitals?
Check after major site changes, and review the Search Console report at least once a month.
Conclusion
A Core Web Vitals test takes a few minutes. Run a quick check with our free website speed test, confirm real-visitor results in PageSpeed Insights and Search Console, then fix the weakest metric first.
