New Google Web Vitals improving your website’s performance

Website health
Google provides feedback to website owners so they can optimise their website. Recently Google started rolling out ‘Core Web Vitals’, a specific set of data signals that you can use to track your website’s performance and improve your users’ experience.
How much Core Web Vitals will affect your ranking is unknown. But considering that Core Web Vitals have a direct bearing on your users’ experience, you should definitely give them some consideration.
Currently Core Web Vitals consist of:

Cumulative Layout Shift (CLS)

You’ve probably experienced visiting a website and clicking only to find that the screen has jumped and you’ve ended up clicking something else.
This is Cumulative Layout Shift (CLS) – the measure of visual stability. The website elements load at a different rate. The website appears to jump around as it loads, creating a poor user experience. To provide a good user experience, pages should maintain a CLS of 0.1. or less.
Ensuring elements on the page have a set height can usually correct this. The browser then knows how much space the element will take up before it loads.
Cumulative Layout Shift (CLS)

First Input Delay (FID)

Poor First Input Delay (FID) makes the user wait for more of the page to load before they can begin interacting.
FID measures interactivity. To provide a good user experience, pages should have a FID of 100 milliseconds or less.
Javascript and the use of third-party code can increase the time the browser takes to load. Improving the management of these assets can reduce your FID.
First Input Delay (FID)

Largest Contentful Paint (LCP)

Largest Contentful Paint (LCP) relates to performance. Think of a slow loading website.
LCP marks the point in time when the main content loads. To provide a good user experience, LCP should occur within 2.5 seconds of when the page first starts loading.
LCP can be affected by poor hosting, inefficient plugins, large images, poorly delivered CSS and javascript
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.

Web Vitals

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)

Lighthouse is a fantastic tool for measuring your website’s performance (and other things). Lighthouse will give you the LCP and CLS metrics. It doesn’t give you FID but does give you TBT (Total Blocking Time). TBT is a calculated value of the things that block loading, while FID is actual data of blocking time the site encounters when loading 🤯.
Note that Lighthouse is based on your actual setup ie the server you use (which is potentially in the same location as your users), your hardware etc.


  • 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.