What Are Core Web Vitals And Why Do They Matter?

Did you know that, as of January 2021, there were 1,197,982,359 websites on the internet? With so much information available, and only a finite amount of time to sort through it all, it’s no wonder that search engines are needed to help us find what we are looking for quickly and effectively. 

But how do search engines work exactly? 

Well, on a simple level, they do all the heavy lifting for us! This clever technology trawls through all those hundreds of billions of web pages to find the most useful, relevant results for our query. 

To do this, search engine giants like Google look at several factors like the keywords used in the search query, the relevance and usability of pages, expertise of sources and the location of the searcher. 

One of the factors Google’s algorithm considers when indexing and ranking web pages is User Experience (UX). That is, how easy websites are to navigate and use. This is achieved by looking at the Core Web Vitals of a site. So, let’s take a look into what these are and how Google measures them. 

What Are Core Web Vitals? 

Core Web Vitals are factors that Google’s algorithm considers to be important to the user experience. They are broken down into three categories, each of which are assigned a specific metric that Google uses to size up a webpage’s user experience quality. These are: 

  • Loading Times 
  • Interactivity 
  • Visual Stability 

Let’s take a look at each of these in depth to better understand what they mean. 

Loading Times 

The signal Google uses to assess page loading times is called Largest Contentful Paint (LCP). The LCP metric tells the search engine how quickly it takes the main content on a page to load. The faster the LCP is, the more useful a page is deemed to be. 

In order to achieve a “Good” score for LCP, pages should take no longer than 2.5 seconds to load its main content. 


The metric Google uses to measure interactivity is First Input Delay (FID). FID tracks how long it takes for a browser to respond to an interaction, such as button click or a form submission. 

To achieve a “Good” score, FID should be 100ms or shorter. 

Visual Stability 

Visual stability simply refers to how stable elements on a webpage are when they are loading. Google uses a metric called Cumulative Layout Shift (CLS) to measure this. On a basic level, Google is telling us that elements on your web page shouldn’t move around and impede a user’s ability to read the information or navigate the site. 

CLS measures the number of times any visible element on a web page moves from its original position. Ideally, you’re aiming for a score of 0.1 to deliver the best experience. 

Why Do Core Web Vitals Matter? 

In May 2021, Google will be releasing a new update to its algorithm which will arguably make UX the second most important ranking factor after content. For this reason alone getting your websites Core Web Vitals up to speed is really important.

More importantly, in our opinion, optimising your website for UX is vital to ensuring potential customers engage with your website and keep coming back to it. After all, how often have you clicked off a website that loads slowly? Or given up when you’re not able to navigate the site properly or keep track of where you are in an article? 

We Can Help! 

While there are a number of tools available to help you understand your site’s current Core Web Vitals and performance, understanding the information they give you and how you can fix any problems that arise is much harder!

If you’re wondering how you can go about upgrading the User Experience of your website, then talk to us! We’ve designed and developed over 1000 websites for lots of businesses ranging from SMEs to international blue chip companies. We also offer bespoke SEO and content marketing services to help solidify your website’s pages in search engine rankings.

For more information about which of our services can help your business succeed, contact us and speak to our experienced Account Managers today!