Cumulative Layout Shift (CLS)
First Input Delay (FID)
Largest Contentful Paint (LCP)
Ways to measure Core Web Vitals
If you have a site with high traffic, data collects in Google Search Console under Core Web Vitals. You may not have enough real world data for this report to run. Noting that there can be a 28 day lag for data to be collected.
Google PageSpeed Insights
Google PageSpeed Insights provides real world data if available, otherwise estimates.
GTmetrix gives a good indication of Core Web Vitals, however the server they use is in Vancouver, Canada. Your server should be close to your users. So if your server is in Sydney, you would expect your real-world results to be better than what GTmetrix reports. The free version also only gives you a score based on the desktop version of your website.
Lighthouse (accessible through Chrome web developer tools)
- Always test your site in incognito mode. Various factors including cacheing, browser add-ons etc can influence the tests. Using incognito mode can eliminate some of these factors.
- Always use the exact URL of your website (either with ‘www’ or without). Redirecting from one to the other during testing will impact your results.
- Although your results for desktop will usually be better than mobile, focus on mobile. Google predominantly uses the mobile version of your content for indexing and ranking.
- Core Web Vitals affects all pages of your website. Rather than aiming for perfect scores, you should aim for over the 75th percentile
Other crucial website health factors are mobile-friendly and using https.
It’s important to note, while Core Web Vitals can impact rankings, a page with fantastic content can still rank well even with poor web vitals.
However, if the user experience is really poor, even great content won’t be enough.
You should definitely give Core Web Vitals some consideration, but don’t let them keep you up at night.