Google’s Core Web Vitals: All You Need to Know

Google’s Core Web Vitals: All You Need to Know

May 24, 2021

Last November, Google announced that the Page Experience Update would roll out in May 2021. As of now, the search giant has delayed the launch till June 2021. However, SEO experts around the world are anticipating what the algorithm changes will hold in store. 

So far, we know that the Page Experience Update will impact ranking signals. Not only will it be prioritising existing signals, but it will also incorporate new ones that are deemed necessary by the search engine. 

These ranking signals will include the Core Web Vitals, 

What are Core Web Vitals?

Core Web Vitals is a set of metrics defined by Google to measure the page speed, performance in responsiveness and visual stability of websites. Namely, Largest Contentful Paint (LCP), First Input Delay (FID) and Cumulative Layout Shift (CLS) are the three web vitals declared as prioritised ranking signals.

One way or another, we can conclude that these three factors ultimately determine the speed of the site. Whether it’s the loading time, the interactivity of the website and responsiveness with regards to various actions performed, we can safely say that maintaining the site’s speed is integral.

What’s interesting is that unlike other updates and guidelines published by the search giant, these are the most clearly defined metrics we’ve gotten yet. What this means is that we now have a clear picture regarding what will affect our site’s rankings. Compared to vague and generalised guidelines, these provide specific details about how a site can perform well enough. However, it should be noted that Google has also declared that useful, unique and quality content will inevitably be preferred. So, apart from other core web vitals, content matters as well.

Since it’s a crucial update that is going to impact SERPs, let’s take a look at the Core Web Vitals in detail:

Largest Contentful Paint

This is the metric that measures the loading performance of the site. More specifically, it looks at the loading time of the largest element of the website. It could be an image, a video or even a substantially large block of textual content that is bigger than the other elements present on-page. The largest content should appear in front of the user as soon as possible. This gives users the satisfaction that their page is being loaded instead of making them wonder if it’ll ever open.

As per the search engine’s guidelines, your LCP should be less than 2.5 seconds to be considered good. At the same time, it can go up to 4 seconds before it is considered poor and penalised as such.

First Input Delay

First Input Delay refers to the time taken by the website to respond to any interaction made on it. For example, if a visitor on your site clicks on any link, button, etc., the time taken by the website to start working on displaying the required information is referred to as FID. 

As we can judge, this metric also targets the speed element of the website, though it takes a rather subtle, direct and specific approach. You will also hear the term TBT or Total Blocking Time being used in place of FID. While both of these point to the same thing, they are different because the former uses lab data rather than field data that is required by the latter. Since we don’t always have field data for the website’s we are working upon, we resort to TBT instead of FID.

Webmasters are encouraged to bring their website’s FID to as low as 100 milliseconds if they want to get positive ratings. Being around 300ms is also okay as this is the bracket that Google deems, ‘Needs Improvement”. Taking any more than 300ms will inevitably result in the website getting penalised.  

Cumulative Layout Shift

CLS focuses on the stability of the webpage with regards to visualisation. We’ve noted several times how websites with images, video and text blocks often glitch out or have difficulties in executing smooth transitions when we scroll. This is something Google terms as a layout shift.

Since it’s clearly an obtrusion for a visitor to have a website that doesn’t remain stable when navigating, Google can’t help but penalise websites that don’t fix this. That is why the search giant has deemed a value of 0.1 or less as the ideal CLS for a website. Going above 0.1 but staying below 0.25 will land you in the “Needs Improvement” bracket. Score higher than this, and you can expect your rankings to fall down quicker than you can say, “Oh No!”

How to Audit and Improve Core Web Vitals?

Now that we know what LCP, FID and CLS are, let’s take a look at how we can measure them before Google does and improve our scores.

Firstly, you need to make sure that you have a paid version of a website crawler like Screaming Frog, PageSpeed Insights API key, and the domain of the website you’re auditing.

Once you connect your PageSpeed Insights API key to your Screaming Frog crawler, you’ll have options to collect different metrics. To name some options that will be available, you can choose from CrUX, Lighthouse Metrics, Opportunities and Diagnostics. Although you can tick all of these boxes, make sure that you don’t run out of your query limit. If you’re close to running out, we suggest taking in Lighthouse metrics as they consist of LCP, TBT and CLS.

Now that you’ve selected the metrics you need to gather, run the crawler and wait for it to finish collecting data. After the API and Crawl loading bars reach 100%, you can export your data with regards to specific fields. This helps SEOs organise data according to various issues, site sections, individual pages, etc.

For example, you can sort the data by applying a filter that allows you to narrow down pages that specifically have PageSpeed issues. You can further navigate through this data and filter columns to find:

  • LCP of 4 seconds or more
  • FID or TBT of 300ms or more
  • CLS scores of 0.25 or more

This will ultimately give you a full list of the pages that are struggling with these issues. Thereby, developers can easily navigate to the problem and focus on solving them. Not only will this help you segment the issues and find generalisations (such as whether the issues are mostly in the blog section, etc.), but it will also reduce the time taken to fix them as well.


After developing an understanding of what the Core Web Vitals are, you can start working upon your website’s performance for the upcoming Page Experience Update that rolls out in June 2021. Instead of watching your keywords dance in rankings and hoping they don’t end up in later pages, it’s advised that you focus on preparing beforehand. 

For businesses and companies that are facing troubles or want guaranteed results, we recommend getting in touch with experts at Zoom Digital. Promising top-tier digital marketing services along with excellent and commendable customer support, you can be sure that your business will be on its way to the top. 

Recent Blog

Case Study

  • Damac

    Driving quality new leads and new buyers for Damac

  • Art Dubai

    Providing innovative software solutions, driving footfall and ticket sales

  • ENOC

    Providing dedicated website management and security solutions

Related Blog

March 10, 2022

How to Know It’s Time to Rebrand?

Rebranding incorporates revolutionizing the inner and outer face of your brand.
Read More

March 3, 2022

How to Get Started with Content Marketing?

Brand awareness has undoubtedly made an immense contribution when it comes to the overall success of emerging businesses
Read More

February 28, 2022

How to Manage Online Customer Reviews

Online customer reviews can be both blessing and a curse
Read More

February 21, 2022

What is Growth Marketing? Here’s All You Must Know

Growth marketing itself is one of the best strategies, it also needs numerous components and tactics to work efficiently.
Read More

February 14, 2022

How Customer Experience is being Enhanced with  Consumer Data ?

Good consumer experience leads to enhanced business endorsement criteria up to 50%.
Read More

February 7, 2022

Marketing on a Shoestring Budget: 10 Top Tips for Small Businesses

Explore the maximum potential of marketing with these top ten tips tailored for small businesses.
Read More

January 10, 2022

How to Set Up Successful E-Commerce Social Media in 2022?

Retail businesses are now focusing on opening their click-and-mortar stores, and having an e-commerce marketing strategy appears more necessary than ever.
Read More

got a project in mind?

get in touch