July 16, 2026 · 7 min read
Core Web Vitals are three metrics Google uses to measure the real user experience on a site: loading speed, responsiveness and visual stability. They are a ranking factor: with equal content, a site that meets them ranks better and keeps visitors longer. Improving them means more traffic and more conversions.
The three metrics and the thresholds to hit
| Metric | What it measures | Good |
|---|
| LCP (Largest Contentful Paint) | Loading speed of the main content | < 2.5 s |
| INP (Interaction to Next Paint) | Responsiveness to user interactions | < 200 ms |
| CLS (Cumulative Layout Shift) | Visual stability (elements that «jump») | < 0.1 |
In 2024 INP replaced the old FID metric, so be wary of guides that still cite FID: they're outdated.
How to improve them in practice
- LCP: optimize and compress images (WebP/AVIF), use good hosting and a CDN, load visible content first.
- INP: reduce and optimize JavaScript, avoid blocking scripts, trim third-party plugins.
- CLS: always set width and height on images and video, reserve space for banners and ads.
How to measure them
Use free tools like PageSpeed Insights and the Core Web Vitals report in Google Search Console, which shows real data from your users. Note: lab tests and field data can differ, because field data depends on real devices and connections.
Performance isn't a technical detail: it's part of SEO and of the customer experience. We look after it in every site we build, it's decisive for an e-commerce that converts, and it goes hand in hand with SEO for small businesses. If your site is slow, ask us for an analysis.
Frequently asked questions
What are Core Web Vitals?
They are three metrics Google uses to measure a site's user experience: LCP (loading speed), INP (responsiveness) and CLS (visual stability). Together they show how fast and pleasant the site is to use.
Do Core Web Vitals affect SEO?
Yes. They are a Google ranking factor: with equal content, a site that meets the thresholds tends to rank better and keep visitors longer, reducing bounce.
What are the ideal Core Web Vitals values?
LCP under 2.5 seconds, INP under 200 milliseconds and CLS under 0.1. Above these thresholds the experience is considered 'needs improvement' or 'poor'.
How can I measure my site's Core Web Vitals?
With free tools like Google PageSpeed Insights and the Core Web Vitals report in Google Search Console, which shows real data collected from your visitors.