Google’s Core Web Vitals: Why speed matters for SEO and conversions

Google recently announced that it plans to launch a huge algorithm update in 2021 which will massively impact rankings. The update is still in its early stages, but it will use existing user experience of a website as well as Core Web Vitals as a ranking signal to evaluate the user experience. 

The search engine giant is trying to make the process as smooth as possible for everyone who wants to get their websites sorted before the update rolls out.

Google will at the Core Web Vitals of a page, as well as these existing page experience metrics: 

  • Mobile-friendliness
  • Safe-browsing
  • HTTPS-security
  • Intrusive interstitial guidelines

What are Google’s Core Web Vitals and how to check yours 

Google's Core Web Vitals was introduced through Search Console in May 2020 - and that's also the best place to find them. 

Google’s Core Web Vitals looks at the following features on a website (warning, jargon ahead): 

  • Largest Contentful Paint: The time it takes for a page’s main content to load. An ideal LCP measurement is 2.5 seconds or faster.
  • First Input Delay: The time it takes for a page to become interactive. An ideal measurement is less than 100 seconds.
  • Cumulative Layout Shift: The amount of unexpected layout shift of visual page content. An ideal measurement is less than 0.1.

In their own words: 

“Core Web Vitals are a set of real-world, user-centred metrics that quantify key aspects of the user experience. They measure dimensions of web usability such as load time, interactivity, and the stability of content as it loads (so you don’t accidentally tap that button when it shifts under your finger – how annoying!)”


At its most basic, Google’s Core Web Vitals looks at how annoying or not annoying it is for users to engage with all the content on your site.

Most importantly, it’s how users experience your website both on desktop and mobile devices and ensuring that the cross-browser experience is as seamless as possible.

While the exact definition of Google's Core Web Vitals might still change before it launches officially, but it all ties in with the user experience. The idea being that it will become easier for algorithms to decipher not only which pages will give readers the answers they're looking for, but to help direct them to pages they'll enjoy visiting.

If the user experience is good, chances are your site will rank higher in the search results. 

But as important as a good user experience is, it’s not going to be the only factor in how your website ranks.

You are probably familiar with the phrase "Content is King". That still rings true. You can have the fastest website in the world, but if it is not serving the user's intent, it's pointless.

The content tie-breaker and rankings clincher 

If you are creating great content and providing a positive user experience, you're likely to get lots of love from search engines.

It means that if two sites with great content go head-to-head, the one that provides the better user experience (which includes fast loading) will more than likely the one that ranks higher. 

As Google themselves put it: 

“A good page experience doesn’t override having great, relevant content. However, in cases where there are multiple pages that have similar content, page experience becomes much more important for visibility in Search.” 

How to check your Core Web Vitals

Although it is recommended that you set yourself up on Google Search Console, it is not mandatory to get an overview of your Core Web Vitals. Using GSC will help you identify problem pages easier, as well as help with a bunch of other things, but you can also use the Google Page Speed Insights tool to analyse individual URLs.  

If you are using Google Search Console already, then it’s simple. 

On your Overview dashboard, scroll down until you see the "Enhancements" section and open the report for Core Web Vitals. You can also access it through the menu on the left. 

Here you will see two different reports - one for desktop and one for mobile. You can open each report and from there, analyse problematic URLs and get some suggestions from Google Page Speed Insights to improve them.

where to find web core vitals search console

Don’t worry if your report is not great. Most of the issues are usually easy fixes and you have a few months before the 2021 Core Web Vitals algorithm rolls out.

If for whatever reason you feel that search rankings do not matter to you or you don’t care about acquiring customers through search (we’re not sure people like this actually exist, but let’s move on) – you might still be interested in knowing just how much of a difference user experience makes in terms of e-commerce conversions.

How to measure Core Web Vitals without Search Console

If you have a website and you're using search (why wouldn't you?) as a way of acquiring users, it is highly recommended that you get set up on Google Search Console. If you're not there yet, though, other tools you can use to measure your Core Web Vitals include

  • Page Speed Insights
  • Lighthouse
  • Chrome DevTools
  • Chrome UX report

Other things to keep in mind for a good user experience 

Mobile-friendly or mobile-first

The majority of web traffic is generated through mobile phones these days, so making sure users have a positive experience on your mobile site is vital. You can use Google’s mobile-friendly test to check, but also run tests yourself on actual phones.

Consider your target market for mobile-friendliness

Smartphones are popular, sure, but they are not the most popular mobile device across the world. In some territories, particularly in Africa, so-called “feature phones” are far more popular. These phones cannot render as much web detail as smartphones can, so it’s important to cross-reference mobile-friendliness on these devices if it is one of your target markets. Ditto for tablet devices – if your target market is more likely to use a tablet, make sure you cross-check how your site renders on one.

Take care of safe browsing

Check the Security Issues report in Search Console for any issues with safe browsing. One of the key factors here is https. If a page is served over a secure HTTPS connection then it will display a lock icon in the browser address bar.

General housekeeping for a good UX

The basic rules of a good user experience also apply in this case. Make sure that the clickable elements on your pages aren’t too close together – and that the links actually work and click through.

If you’re deleting a page for whatever reason, consider whether it needs to be redirected if it is linked to from elsewhere.

If your site has been running for many years, be sure to go back to older content and tidy up anything with low-quality images. This is especially important for so-called legacy sites – websites that have moved from one platform to another over several years.

And finally, be a customer. Have you personally gone through your website’s entire checkout process on both a desktop and a mobile phone? Did you enjoy it? If it were not your website, would you use it again and would you recommend it to friends and family?

The best advice for thinking like a customer is to see if you can break something – literally. Not because you want to destroy your site, but you need to try and catch any niggles that might hinder a customer from converting.

Does the back button take you somewhere you did not want to go? Does the navigation not work correctly when you use it on your mobile? Once you have had a proper rummage through your own site, pass it along to somebody a bit more technically challenged and see how they find it.

Most importantly, always be open to feedback. The site is your baby, sure, but other people might not always love your baby as much as you do. It’s important to find out what you can do to get them as besotted with your website as you are.

And all of that brings us to the pertinent point of why page speed is such a big deal even before it has been officially rolled out as a ranking signal. 

The impact of Page Speed on conversions

Over the years, an increasing number of studies have found that website performance has a measurable impact on conversion rates. The faster the page, the higher the conversion rate.

And while conversion rates might traditionally refer to e-commerce, they’re also relevant for websites with a content focus. Even if you’re not selling anything, you want users to increase their session times and become returning users.

What’s the speed benchmark for conversions?

speed impact on conversion rate

A study done by found that  47% of customers expect a webpage to load in 2 seconds or less. If you’re hoping to convert users, this is what the study found: 

  • Pages that loaded in 2.4 seconds had a 1.9 per cent conversion rate
  • At 3.3 seconds, the conversion rate was 1.5 per cent
  • At 4.2 seconds, the conversion rate was less than 1 per cent
  • At 5.7+ seconds, the conversion rate was 0.6 per cent

There have been other studies that show similar results. 

Walmart saw conversions increase by 2% for every one-second load-time improvement while COOK increased conversions by 7% by reducing page load time by 0.85 seconds. Mobify found that each 100ms improvement in their homepage's load time resulted in a 1.11% increase in conversion.

Those are some impressive stats and they can have an astronomical impact on revenue.  If a site generates 10 million in revenue each year and conversion rates increase by just two per cent, that's 200 000 more in revenue.

As mentioned, the conversion rate doesn't have to mean e-commerce sales. In another study, when Firefox reduced its load time by an average of 2.2 seconds, downloads jumped by 15.4% which translated to an additional ten million downloads each year.

Faster loading times could also result in customers cart values increasing - which is exactly what happened with When they halved their load times, the conversion rate increased by nine per cent while cart value increased by 11 per cent.

Those are some big numbers.

While Google is certainly not the only search engine out there – and definitely not the only source of attracting and retaining customers – Core Web Vitals are essentially just best practice for the web.

If you’ve not been paying attention to your site’s speed over recent years (especially on mobile) – it might feel quite overwhelming when you first see all those red lines shouting at you.

Do not be alarmed. While the suggestions might sound very technical, most of these can be solved quite simply.  If you use a platform like WordPress or Shopify, they can almost always be solved with a plugin (WordPress) or an app (Shopify).

Some of the biggest problems centre around things like images being too large and getting too carried away with myriad fonts, colours and animations.

Keep it simple, unless you’re the Space Jam website that still lives on Geocities. Wait, you've never heard of Geocities? That's a tutorial for another day, then. 

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