All you need to know about the Google Core Web Vitals

All you need to know about the Google Core Web Vitals

Core Web Vitals is the new buzz term in the SEO world, and we’re here to decode it for everyone trying to improve their Google rankings in 2021. 

As we all know, the internet hosts trillions of web pages, and it would not be easy to find what you’re looking for if it wasn’t for Google’s algorithm. With the right metrics and ranking criteria, Google helps users locate the most relevant web pages within a few seconds. And it keeps on evolving year after year. From keyword density and page speed to overall user experience, Google core algorithm update considers every factor contributing to making web search a simple, quick, and efficient process. 

To ensure that only quality content makes it to the top rank, Google has churned out a new set of metrics called “Core Web Vitals” in 2021. This article discusses them in detail and throws light on how you can optimize your web pages after this new development. Let’s begin!

So, what are Google core web vitals?

What happens when you visit a doctor? 

They first check your vitals, right! 

And then, factors like your blood pressure, weight, and age help them assess your current health conditions. 

Similarly, the latest Google SEO update defines specific criteria to judge whether a web page provides pertinent information and a pleasant user experience. Referred to as core web vitals, they assess the quality of your on-page experience and conclude whether the web page is worthy of a good rank or not. 

These Google core web vitals are an addition to already-known guidelines for good ranking like the following:

  • Mobile-Friendliness: Whether a page is fully responsive and mobile-optimized.
  • Secure Browsing: How prone a web page is to virus and malware attacks.
  • Presence of Pop-Ups: If your page has any intrusions in the form of pop-up ads. 
  • HTTPS: If your page is HTTP encrypted or not.

And finally, in 2021, an updated set of core web vitals have joined the bandwagon. What sets them apart is that they’re measurable, actionable, and define the user experience in more transparent terms. With proper understanding, one can improve their UI/UX design and boost rankings. Let’s find out what they are –

  • Loading (LCP): How fast does the information appear on the screen?
  • Responsiveness (FID): How quickly does the page react to a user’s input?
  • Visual stability (CLS): Does the appearance of dynamic content like pop-up ads cause displacement in the readable content?



Up till now, user experience and quality content have been vague terms, but with this new update, Google has attempted to define them with an actionable formula. Each core web vital has a recommended threshold with which you can measure and maintain your SEO score. By keeping a check on these rules, you can predict and plan your SEO strategy in a much more constructive manner. 

Here’s a detailed look at these criteria and how you can incorporate them into your long-term content plan:

LCP (Largest Contentful Paint)

To put it into simple words, LCP refers to the time taken for the most prominent content to load on a web page. It can be your main banner or a video on your webpage; basically, anything that would catch a user’s attention when they visit your webpage.

What makes it different from earlier metrics is its emphasis on a user’s journey. It judges a page from a user’s viewpoint and lets you know whether your web page successfully creates a lasting impression.

Let’s face it – every page has certain elements which are more impactful and eye-catching than the others. For example, if a webpage has a few text lines and a large image, a visitor would first glance at it. However, if that image takes several seconds to load, the user is more likely to lose interest and bounce from the site. 

LCP redirects your focus towards that particular part of your webpage, which will leave an impression on the user and its optimization. It is simple to understand, interpret and implement. 

It breaks down your goal of improving the overall page speed into small, measurable units where you first ensure that the largest visible image or text block appears faster than the rest. 

Moreover, the Google SEO update has also defined a good score so that you can measure your webpage’s performance using Search Console and PageSpeed insights. Here’s what your LCP score would mean –

  • If the score is under 2.5 seconds, it is a good LCP
  • If it is between 2.5 to 4 seconds, it needs improvement.
  • If it is anything above 4 seconds, then it’s regarded as poor LCP.

FID – First Input Delay

Let’s begin this with a quick example – you just found the eBook you were looking for, and you need to fill out a form before downloading it. You fill it out and click on the submit button; however, the button takes too long to respond. That is what is known as the first input delay or FID. 

In other words, the time taken by your page to respond to the first interaction request by a user is called first input delay. These requests could be anything like a redirection link, sign up page, login button, search option, or accessing the menu. 

Believe it or not, these fractions of a few seconds are essential for the overall user experience. In today’s world of instant gratification, even a delay of microseconds could frustrate a user. However, we also need to understand that a browser needs time to respond to a request, and with increasingly complex web pages, its performance becomes sluggish.

It is where the importance of FID comes into picture. Instead of measuring and optimizing the entire web page’s performance, you can identify the first interaction point and focus on its enhancement.

Like LCP, you can also measure your FID score to understand how your web page performs as per this metric.


  • If the score is under 100 ms, it is good.
  • If the score is between 100 ms to 300 ms, it needs improvement.
  • Anything over 300ms is considered a poor score.

Cumulative Layout Shift (CLS)

This is the latest addition to the long list of Google core web vitals and, again, puts user experience at the top of a web designer’s priorities.

Does it ever happen to you that you visit a webpage and suddenly encounter an ad that covers the entire screen? Now, you have to either close the ad or go back to the original page if you’ve clicked the ad by mistake? 

These elements make the visual layout of a web page unstable and often frustrating for a visitor. The Cumulative Layout Shift metric aims to analyze a web page’s visual stability and discourages any unexpected layout shifts on a page.

However, you need to remember that a layout change is terrible only if it’s unexpected and abrupt. If the user clicks on a cascading menu and a new layout appears, it won’t impact your web page’s CLS score. When a shift happens as a response to direct user actions, it is expected and acceptable. 

Google measures all the unexpected shifts on a page as it renders and combines it with the distance that each layout shift covers to develop a CLS score. Ideally, the score helps you find out where your web page stands- 

  • If your CLS score is below 0.1, then it is considered good.
  • If your CLS score falls between 0.1 to 0.25, then it needs improvement
  • If your CLS score is above 0.25, then it is rated as inferior

Maintaining Core Web Vitals for a Better Ranking in 2021

Google algorithm is nothing but a reflection of evolving users’ expectations. In 2021, a web user is competent and expects a stable, straightforward, and simple-to-navigate web experience. If your approach to web design and development has always been user-centric, you need not worry.

However, a few tweaks as per the latest Google SEO update to keep your web pages up to date and at the top won’t hurt. With the Google core web vitals in place, you will be on your way to make your website visually appealing and enriching to your users. 

Ultimately, what matters is how well you know your users and what efforts you put in to provide them with a good experience.

  • #Core Web Vitals
  • #Cumulative Layout Shift
  • #Google Algorithm
  • #Google core updates
  • #Largest Contentful Paint


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