Why you need to know about Core Web Vitals for SEO

A winning SEO strategy isn’t just about keywords. Core Web Vitals are some of the latest ranking factors you need to know. Just be careful not to prioritise them ahead of great content, UX or design.
When we think about search engine optimisation or SEO, we usually think about optimising the right keywords. Maybe some of us will think about other aspects – such as improving link authority or user experience. But the fact is there are as many as 200 distinct Google ranking factors to take into account, and they’re not all keyword-related.

Page experience signals matter

It’s increasingly important to target page experience signals for a winning SEO strategy.
I’ve already touched upon this a little bit in my previous article on how improving your UX improves your SEO, but I think we need to dig deeper.
In the article, I discussed aspects like page speed and accessibility. Although I dipped a toe into Core Web Vitals – a set of metrics launched by the Chrome team – they’re now being incorporated into Google’s page experience signals for ranking.
This currently includes mobile-friendly, safe browsing, HTTPS, and intrusive interstitials metrics. So I figured it’s a good time to take a closer look at the upcoming changes to the algorithm.

What are Core Web Vitals?

Core Web Vitals were first announced and introduced in May 2020 as a ‘set of metrics that measure real-world user experience for loading performance, interactivity, and visual stability of the page’.
Three metrics fall under the ‘core web vitals’ umbrella: LCP, FID, and CLS.

1. LCP – largest contentful paint

LCP measures how long it takes for the biggest visual (usually an image or video) on your website to load from when your user requests the URL.

2. FID – first input delay

FID measures the time between a user clicking on an interactive element on your website for the first time (e.g. clicking a link) and your website responding to that request.

3. CLS - or cumulative layout shift

CLS measures how much the visuals or element blocks on your website move during the loading phase. For the best experience, elements should not move.
Ultimately, these three metrics examine page speed and how it impacts the overall user experience.

Where does SEO come in?

Shortly after the announcement of Core Web Vitals, Google announced an upcoming change to their ranking algorithm. This would ‘introduce a new signal that combines Core Web Vitals with our existing signals for page experience to provide a holistic picture of the quality of a user’s experience’.
The new ranking algorithm was initially launched in mid-June 2021. Google stated that they expect the full-page experience update to be 100% complete and rolled out to all users by the end of this year.

Why do Core Web Vitals matter?

The question is, why do Core Web Vitals matter so much to Google?
Google’s aim is clear: to offer the best, most relevant results to users. Google wants to provide results that engage users, and their research shows users hate slow websites.
  • A 2-second delay (from 1-3 seconds) increases page bounce rate by 32%
  • A 4-second delay (from 1-5 seconds) increases page bounce rate by 90%
  • A 5-second delay (from 1-6 seconds) increases page bounce rate by 106%
  • A 9-second delay (from 1-10 seconds) increases page bounce rate by 123%
And so Google naturally wants to reward high-speed websites – sites that delight users – with a better page ranking and SERPs position. Slow sites get penalised with a lower ranking and position.
But there’s one vital piece of advice that I can give all businesses right now. You shouldn't focus exclusively on page experience signals for SEO.
Are Core Web Vitals important for SEO? Absolutely. But you can’t afford to forget about other ranking factors. Google states that ‘a great page experience doesn’t override having great page content’.

How’s your site doing?

If you’re not sure how your website is performing in terms of the three Core Web Vitals metrics, you can easily measure your impact with:
  • Chrome User Experience Report
  • PageSpeed Insights
  • Search Console’s Core Web Vitals report
  • Web Vitals extension for Chrome

What should you aim for?

  1. LCP: Your largest page element should load in less than 4 seconds. Anything under 2.5 seconds is preferable for SEO, and anything over 4 seconds needs some urgent attention.
  2. FID: Your page should respond to a user request in less than 300ms to keep visitor attention. Under 100ms produces the highest-ranking boost, while anything over 300ms could result in SERPs penalties.
  3. CLS: You should be aiming for a big fat zero, which means your elements don’t shift at all during loading. A result of 0.1 is still considered good, while anything above 0.25 needs work.
The good news is that you can optimise for success. This may be as simple as making sure you include width and height attributes to your images to improve your CLS score.
It could be something more complex, like optimising JavaScript execution for lower FID response times.
Whatever it is, we can help. At Tangent, we work with businesses to improve the on-page experience and leverage great UX for winning SEO strategies.