Why Google Core Web Vitals Are Becoming A Ranking Factor

February 26, 2021

Kerrie Ashall

When it comes to ranking factors, there are many ways that search engines analyse certain metrics in order to rate web pages. We’ve previously looked at how Google ranks web pages based on content with Passage Ranking, and now it looks like there is going to be another method for measuring page performance this year.

Back in November 2020, Google announced that Core Web Vitals were set to become ranking signals by May 2021. This will tie into the Page Experience Update, which Google previously stated with include Page Experience as a ranking signal. Along with Core Web Vitals, other web vitals like mobile-friendliness, safe browsing, HTTPS and non-intrusive interstitials will be considered when measuring Page Experience.

But what exactly are Core Web Vitals and what do they mean for SEO?

What Are Core Web Vitals?

When you’re wondering what types of things Google is analysing on your site, you need to check your page load speeds, the interactivity and how your site performs on desktop and mobile devices.  This where the Core Web Vitals come in. As mentioned, Core Web Vitals tie into the Page Experience which is based on signals used to record user experience on web pages. Core Web Vitals are used to measure the speed, responsiveness and overall performance of your page based on users’ experience.

There are 3 core metrics that make up these web vitals:

LCP (Largest Contentful Paint) – Loading: This analyses how long it takes for the page’s main content to load. 2.5 seconds or faster is the ideal time.

FID (First Input Delay) – Interactivity: How long it takes for a page to become interactive. Ideally, this would be less than 100 milliseconds.

CLS (Cumulative Layout Shift) – Visual Stability: This records how much visible content shifts in the page content. A good measurement would be less than 0.1.

These metrics are instrumental in filtering out high-quality web pages, and if your web page produces a positive Core Web Vital report, then you may witness a small increase in rankings.

How To Record Core Web Vitals

There are several ways that you can measure Core Web Vitals (it’s worth using a mixture of these tools to sufficiently audit your site):

  • PageSpeed Insights – This tool is used to measure site performance on mobiles and desktops. It’s powered by Lighthouse, an open-source automated tool, Lighthouse can be run against any web page and has audits for SEO, accessibility and performance.
  • Web Vitals Extension – these act as ‘quality signals’ that offer feedback on layout, loading and other metrics.
  • Chrome DevTools – a set of web developer tools built into the Google Chrome browser, these help you to edit pages by quickly detecting page issues.
  • Search Console – helps you to measure your site’s search traffic and maintain your ranking in SERPs. You’ll be able to see which sites link to yours, and also receive alerts when indexing issues or spam is detected on your site.
  • Chrome UX Report – also known as CrUX, this provides real world results thanks to its page experience score being based on real-life user metrics. This offers an invaluable insight for site owners wanting to learn more about the user experience they offer.

What This Means For SEO 

It’s not news that good site performance and loading speeds are necessary for sites to rank well, but there are still sites that don’t know how to utilise Google tools to improve their web pages. Site owners may also not realise how Google ranks sites based on loading speed; for instance, if a web page takes too long to load, the user will ultimately lose patience and close the tab, or ‘bounce’ before the loading finishes. This activity gets picked up by the search engines and contributes towards your site’s ranking; check out our previous article for more information on bounce rates.

Core Web Vitals aren’t necessarily something to be afraid of, but can instead be employed to make much-needed alterations to your site’s layout.  In a study by Google, they analysed millions of page impressions to get a better understanding of how the page metrics affected the user experience, and found that users were 24% less likely to give up on page loads when the site met the Core Web Vitals requirements.

This update will have a significant impact on those looking to boost their rankings, though it should be noted that improving the score of your page experience alone won’t give you that much-needed push. Google has stated that page experience is one of many factors considered in ranking sites. Still, if you think your site is in need of a boost, then looking to improve your Core Web Vitals might be something worth exploring.

How To Improve Your Scores

These are just some of the ways that you can improve your Core Web Vitals scores:

Largest Contentful Paint

  • Upgrade your web host
  • Remove large page elements
  • Optimise images


First Input Delay

  • Minimise JavaScript
  • Use a browser cache: this will load content on your page faster


Cumulative Layout Shift

  • Use set size attribute dimensions
  • Load content downwards
  • Check for FOIT (Flash of Invisible Text)


Final thoughts

The good news is that you still have until May before Google rolls out its latest ranking algorithm, ensuring you have plenty of time to measure and record your Core Web Vitals. Essentially, these vitals are another example of how Google detects issues in web pages, so if you want to get ahead and smooth out any errors that could be hindering the user experience, you’d be on the right track. User experience can make or break your site’s potential, and it really isn’t an area you can forgo.

Recent Work

  • Glide

    The Glide group is the UK’s market-leader in household utilities, broadband, connectivity and communications.

  • The Fry Group

    Established in 1898, the experts at The Fry Group assist expats based in the UK, Europe, and the Far East with all aspects of their financial planning.

  • Helping Hands Home Care

    The team at Fibre are absolute experts in SEO. Working together we have dramatically improved SEO performance particularly at a local level.


Ready to get started?