How to check your website's Core Web Vitals
Core Web Vitals are the three metrics Google uses to judge how a page actually feels to use, not just how fast it loads on paper. Checking them takes two minutes and needs no account.
What the three metrics actually measure
Largest Contentful Paint (LCP) times how long the biggest visible element takes to render - your hero image or headline, usually. Interaction to Next Paint (INP) measures the delay between a click or tap and the page responding. Cumulative Layout Shift (CLS) scores how much content jumps around as the page loads, like a button moving just as you go to tap it.
Where to check them for free
PageSpeed Insights (pagespeed.web.dev) gives both a lab test and, for sites with enough traffic, real visitor data pulled from the Chrome User Experience Report. Search Console's Core Web Vitals report groups your actual pages by pass or fail at scale, which matters more than any single-page score.
Field data and lab data measure different things
Lab data is one simulated test run on Google's servers - useful for debugging, easy to game with a fast connection. Field data is the real experience of your actual visitors, on their actual devices and networks, averaged over 28 days. Google's ranking system uses field data. If your lab score is excellent but field data is poor, trust the field data.
What counts as good
Google's thresholds: LCP under 2.5 seconds is good, up to 4 seconds needs improvement, beyond that is poor. INP under 200 milliseconds is good, up to 500 needs improvement. CLS under 0.1 is good, up to 0.25 needs improvement. A page needs all three in the good range to pass the overall assessment - one poor metric fails the page.
The fixes that move the needle most
For LCP, compress the hero image and make sure it isn't hidden behind render-blocking scripts. For INP, cut third-party JavaScript that runs on every click - chat widgets and analytics tags are frequent offenders. For CLS, set explicit width and height on images and ads so the browser reserves space before they load.
Checking it across your whole site, not one page
A single-page test tells you about one URL; most sites fail vitals on specific templates - product pages with too many embeds, or a blog theme with unoptimised images - while the homepage looks fine. AuditHQ's Technical suite pulls real Core Web Vitals data as part of the free scan, so you see which pages and which metric are actually the problem.
Frequently asked questions
Are Core Web Vitals a confirmed Google ranking factor?
Yes, as part of the page experience signals, though content relevance still outweighs them. Vitals rarely explain a ranking gap on their own, but a page in the poor range is competing with a handicap, and poor vitals reliably correlate with lower conversion rates regardless of any SEO impact.
Why do my scores differ between PageSpeed Insights and other tools?
Different tools test from different locations, connection speeds and device profiles, and lab scores vary run to run by nature. Field data, the real visitor average, is far more stable and is what Google actually uses to rank - treat lab scores as a debugging aid, not the final verdict.
How often should I re-check Core Web Vitals?
Monthly is reasonable for most sites, and always after adding a new plugin, widget or redesign - these are the most common causes of a sudden regression. Search Console updates continuously, so a quick glance there catches drift before it affects meaningful traffic.