A Breakdown of the Upcoming Core Web Vitals Google Update

The world of SEO is about to be hit with a large Google update, which I wrote about at the end of last year, in core web vitals.

Essentially, Google is adding three new ranking signals to ultimately judge a website’s overall page experience. These new signals are grouped together in what is being called the ‘core web vitals – and this update will be rolled out in May 2021.

Core web vitals will start to make up 3/7 of the signals Google uses to judge a website’s “page experience” score – as detailed in the image above. If you have access to a Google Search Console property, you’ll already be able to see this data inside there – to give you a slight head start. Alternatively, you may have seen these terminologies and metrics within GTmetrix, when analysing a website’s speed.

The metrics include:

  • Largest Contentful Paint (LCP).
  • First Input Delay (FID).
  • Cumulative Layout Shift (CLS).

Why is the core web vitals update being rolled out?

Well, pretty much everyone who has ever used a website, ever, will be aware when a website has a bad user experience, or when a website is particularly easy, or even perhaps enjoyable, to use. So, the core web vitals update is ultimately Google teaching this awareness to its algorithm and then wielding it as a significant ranking factor. As we all want our search queries to return back the best websites, and this is another step towards achieving that.

Google themselves explained the decision:

“Through both internal studies and industry research, users show they prefer sites with a great page experience… Great page experiences enable people to get more done and engage more deeply; in contrast, a bad page experience could stand in the way of a person being able to find the valuable information on a page.” – Google Webmasters Blog, May 2020.

In short, Google decided they needed a better and more efficient way to ‘size up’ a website’s user experience, and, this was their conclusion.

So, what are the metrics?

Largest Contentful Paint (LCP)

LCP, short for ‘largest contentful paint’ is a measurement of how long it takes a web page to load from the user’s point of view. Essentially the time from you clicking on a link to seeing the web page.

You want to have every page on your website to hit LCP within 2.5 seconds.

First Input Delay (FID)

LCP is the first gate, and FID is the second. FID, short for ‘first input delay’ is a measurement of the time it takes for a user to interact with your web page.

An example of a user interaction would be something like filling out a form or clicking a menu drop-down button.

Cumulative Layout Shift (CLS).

CLS, short for cumulative layout shift is the measurement of how stable a web page is. In short, you want the elements of your webpage to not be moving around the page as the page is loading.


To summarise, the core web vitals update is just around the corner. And, if your website isn’t ready for it, that will be a very bad thing, indeed.


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