Core web vitals

In most cases, Google algorithm updates are too small to notice. But every now and then Google introduces an update so fundamental that it changes the way we do SEO forever.

Panda, Penguin, Hummingbird, Medic, and Bert, together with mobile and core updates have all had a profound effect on the way we think and act about websites and content.

Then in June 2021, Google updated its organic ranking algorithm to add Core Web Vitals as a ranking signal. This recent algorithm change may affect your website’s SEO performance, including its organic traffic, leads, and sales.

In this article, we will investigate why this update was introduced, how it works, and what adjustments you need to make to your business’s SEO strategies in response.

Table of Contents

What’s The Problem?

These days, fast web experiences are key across all industry sectors. People want to quickly find relevant information, pay bills, order a product, and browse company reviews. And if the source of information doesn’t respond immediately, they are likely to abandon the site and move on.

Key facts to consider: 

  • Modern consumers form an opinion of your entire business based on your website, how quickly it loads and becomes interactive.

Search for your local coffee shop in Google. Count the number of seconds it takes to load. Monitor how your patience wavers as the seconds go up. Do you just want to click away?

  • The longer the page takes to load, the higher the bounce rate, which means you lose website traffic.

 Google found out that as page load time goes from 1 to 10 seconds, the probability of a mobile site visitor bouncing – that is leaving the website without taking any action – increases 123%.

  • A slow load speed on a webpage can lead to a lack of sales conversions and a general loss of traffic, particularly on mobile phones.

While more than half of overall web traffic comes from mobile, conversion rates are lower than desktop. It’s clear that speed equals revenue! A study of 900,000 mobile ads’ landing pages, spanning 126 countries, confirmed that most mobile sites are slow and bloated with too many elements (Ithinkgoogle).

According to the DeepCrawl Core Web Vitals Guide, mobile websites have doubled in size since 2016 (800kb to 2000kb) and desktop versions have grown by more than 1/3 (1,400kb to 2,100kb).


What Are Core Web Vitals? 

Core Web Vitals are a set of speed performance metrics essential to delivering a superior user experience on the web. The new page experience signals combine Core Web Vitals with existing search signals, such as mobile-friendliness, safe-browsing, HTTPS-security, and intrusive interstitial guidelines.


The Core Web Vitals help site owners measure their website’s user experience when it comes to loading, interactivity and visual stability.

  • Loading– Largest contentful paint (LCP): The time it takes for a page’s main content to load from the point of view of an actual user. This usually involves the largest element that loads in on the initial viewport, typically an image or video.   An ideal LCP measurement is 2.5 seconds or faster, and longer than 4 seconds is poor.


  • Interactivity– First input delay (FID): The time it takes for a page to become interactive from a user point of view.  In other words, from when a user first interacts with a page and when the browser starts processing that interaction. An ideal measurement is less than 100 ms, and long than 300 ms is poor.



  • Visual stability – cumulative layout shift: The amount of unexpected layout shift of visual page content when a page is loaded. An ideal measurement is less than 0.1 and higher than 0.25 indicates poor experience.


As Google explained:

“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!)”

User experience metrics that have already been around for some time and compliment the Core Web Vitals include:

  • Mobile friendly – Page is designed and optimised so it’s responsive across devices and screen sizes.
  • Safe browsing – Website is safe to open browse, and website items are safe to download.
  • HTTPs – Website encrypts all user data, including credit card details and browsing history.
  • No intrusive interstitials – Website does not feature extraneous content, such intrusive pop-up ads, that appears over most of the page.


Why Does It Matter?

The Core Web Vitals, along with existing page experience metrics, help Google decide which websites to rank.

  • It’s all about user experience. If Google sees a website that provides a high-quality user experience based on the Core Web Vitals metrics, it will likely promote the page higher in search engine results pages (SERPs).


  • Let’s not forget, however, content is still king. Google will often penalise low quality and thin content for not meeting its criteria. It rewards well-researched, relevant content with higher rankings in SERPs.

As Google states:

“A good page experience does not 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.”

  • Google’s Core Web Vitals labels will also show which websites provide a good user experience. This gives it information about the quality of a web page, which helps users choose the search result they want to visit.


As Google states:

On results, the snippet or image preview helps provide topical context for users to know what information a page can provide. Visual indicators on the results are another way to do the same, and we are working on one that identifies pages that have met all the page experience criteria.

It turns out, many pages would not qualify for this label as they are not optimised well enough to pass a Core Web Vitals assessment.


What’s The Solution?

There may ways to measure Core Web Vitals. The tools that will help you improve page experience include:


  • Search Console’s Core Web Vitals report to identify opportunities for improvement.

You can find your site’s Core Web Vitals data in the “experience” section of your Google Search Console account.


In this case, Google identified 71 URLs affected by poor loading speed, and LCP could be improved on mobile phones.



  • Google PageSpeed Insights

PageSpeed Insights analyse the content of a web page, then generate suggestions to make that page faster. You can also check your LCP, FCP and CLS scores using this tool, and make changes to help your page load faster.

It’s a valuable tool because it actively tells you what the problem is on each page, and how it can be fixed. When Google specifically gives you information to improve performance then you should make that a high priority.

This valuable data comes from Chrome User Experience Report, and is powered by real user measurement of key user experience metrics.


  • Lighthouse – Lighthouse is an automated website auditing tool that helps developers diagnose issues and identify opportunities to improve the user experience. LCP and CLS are also available in Page Speed Insights. But the third new metric included in Lighthouse, Total Blocking Time (TBT), correlates with the field metric First Input Delay (FID).


  • AMP Framework


Google announced that 60% of Accelerated Mobile Pages (AMP) domains pass Core Web Vitals, compared with just 12% of non-AMP domains. You can build AMP pages to have less JavaScript and CSS. This in turn helps content load quickly as website becomes more interactive. AMP uses a layout system that predefines and declares the size of elements in advance, ensuring there’s never a poor-quality experience for the user. Note that AMP isn’t the right solution for every website, so it’s crucial to first do research to see if’s right for yours.


To sum it up, Google provides the following suggestions for web developers to get a complete view of website performance speed issues:

  • Use Lighthouse in DevTools to optimise your user experience and ensure you are setting yourself up for success with Core Web Vitals in the field.
  • Use PageSpeed Insights to compare your lab and field Core Web Vitals performance.
  • Try out the Chrome User Experience Report API to easily access how well your original URLs have performed against Core Web Vitals over the past 28 days.
  • Use the experience section and footer in DevTools Performance panel to dive deep and debug against specific Core Web Vitals.
  • Use Search Console’s Core Web Vitals report for a summary of how your origins are performing in the field.
  • Use the Web Vitals Extension to track a page’s performance against Core Web Vitals in real-time.


How to Boost Site Performance?

  • Use native browser support and reduce using JavaScript or CSS libraries
  • Load only necessary assets
  • Enhanced code output
  • Avoid having multiple redirects
  • Maximise rendering and backend processes
  • Optimise and refine internal CSS and JavaScript
  • Have a flat website architecture that avoids duplicate content
  • Ensure images are optimised to be the smallest size possible
  • Apply any specific feedback Google provides with free tools
  • Ensure that improvements are done for both desktop and mobile


What are The Benefits of working with Living Online?

Web users are more demanding than ever before. Business owners and marketeers who deliver fast and spotless website experiences will reap the benefits.

If you want to provide excellent user experience, your website’s performance needs to be top notch. It is obvious that while quality content still reigns supreme, the technical side of your SEO based around your website speed will gain more importance.

Our job is to make sure that your page is providing optimal user experience, based on its page experience signals so that it is likely to rank it higher in search results. We are highly experienced in diagnosing and fixing website speed issues across e-commerce, interactive and service-oriented websites.

Contact Living Online Today and get a website UX audit for your business.