Google is always creating chaos with its algorithm updates.

This time, it’s the Core Web Vitals that’s created a buzz in the webmaster and SEO communities.

Core Web Vitals bring a concrete way of measuring one of the most valuable web signals – User experience.

For years, optimising for speed has been the primary focus for better rankings. With this change, webmasters will have to consider how the page actually feels to the real-world user.

So, are the Core Web Vitals the next thing to add to your SEO Checklist?

What are Core Web Vitals?

Core Web Vitals are a set of metrics designed to reflect the real-world performance of a web page.

Specifically, Core Web Vitals consist of three metrics: Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Shift Layout (CLS).

In short: the LCP, FID, and CLS are scores given to your web page based on your page’s overall UX. These metrics are going to be part of Google’s “page experience” score.

No, you’re not reading a research thesis! We’ll simplify all that in a moment.

Basically, it’s Google’s approach of quantifying two essential quality signals – Website Speed and User Experience.

Let’s understand what each of these terms means.

Largest Contentful Paint

Largest Contentful Paint or LCP expresses the actual “loading time” of a web page.

It’s the time taken for the “largest element” on a page to render on the user’s screen after clicking on a link.

This largest element can be an image, a video, or a large block of text.

The LCP metric only considers the content that’s “above the fold.” So you don’t have to worry about anything lower down on your page.

Google considers the ideal LCP measurement to be 2.5 seconds or lower.

As the LCP mainly concerns with the loading speed of your page, it will primarily be affected by factors like:

  • Host speed and server response time
  • Caching
  • Content Delivery Network (CDN)
  • JavaScript and CSS optimisation
  • Heavy images/videos and having too many plugins or scripts will negatively impact the LCP.

First Input Delay

The second Core Web Vital you need to optimise is the First Input Delay or FID.

FID is how long the web browser takes to “respond” after the user first interacts with your web page.

But what do we mean by “interaction?”

Basically, the first thing the user DOES on your page (apart from scrolling):

  • Clicking on a link/button
  • Typing into a text field
  • Clicking on a menu option, etc.

The FID should be less than 0.1 seconds (100ms) to meet Google’s standards.

If you run a content-focused website/blog, chances are you don’t need to stress about this metric.

On the other hand, for sign-up pages, lead magnets, login pages, etc., which rely on users quickly clicking on something, FID becomes super important.

The following things could improve your FID scores:

  • Removing unnecessary third-party scripts: Like LCP, third-party scripts (YouTube, Google Analytics, async scripts) will lower the FID score.
  • Optimising CSS and JavaScript: Complex CSS styling or long JS execution can have a dramatic effect too.
  • Caching: With proper browser caching, your page content and JS/CSS scripts load faster. This ensures faster response times.

Cumulative Layout Shift

Picture this – You’re about to click an element on a page, and suddenly the entire content shifts. You click on a random banner ad instead.

Has this ever happened to you?

It happens A LOT, and it’s so annoying!

Well, the good news is that Google understands this. Their third Core Web Vital will penalise pages like these.

Cumulative Layout Shift or CLS is a measure of the total unexpected layout shifts that occur as the page loads and while the user stays on it.

In other words: It represents the “visual stability” of the page.

The lesser the content bounces around the viewport, the more visually stable it is.

In order to pass the Core Web Vitals threshold, your CLS score should be 0.1 or lower.

Some tips that can help you pass this metric are:

  • Minimise pop-up ads. If you can’t, allocate reserved space for ads.
  • Use pre-defined dimension attributes for media (audio, video, and image).
  • Preload fonts.
  • Ensure that any element is only added or removed upon user interaction.

Are Core Web Vitals Important?

Google plans to incorporate the “page experience score” as an official ranking factor starting from mid-June 2021.

Page experience is going to constitute a set of signals that signify the overall user experience, including:

  • Mobile-friendliness
  • Safe-browsing (lack of malware, risky scripts, etc.)
  • Intrusive Interstitial Guidelines (not having interstitial pop-ups)
  • And most importantly, Core Web Vitals.

The Core Web Vitals make up a major chunk of this score. This essentially means that these metrics are going to play a significant role in your rankings.


If you don’t want to be cursed by the search engine gods…

And if you don’t want your competitors to edge you out of the first page of Google…

Core Web Vitals are kind of important.

Impact of Core Web Vitals on Search Results and Rankings

With page experience becoming an official ranking factor and the Core Web Vitals constituting a healthy portion of the score, it’s safe to say that this update WILL affect the search results.

But the question is: HOW? And by HOW MUCH?

We know that Google wants to deliver the best web experience to its users. The Core Web Vitals will push more and more webmasters to build websites that are fast and responsive.

Consider the following scenarios:

  1. Your page is among the few relevant pages that match the search intent:
    Google will put your page above the non-relevant pages even if your site doesn’t meet the Core Web Vitals standard.
    Example: When a user searches for your company’s name, or your site is the only one to have written a specific product review, etc.
  2. Your page is competing against several other competitors for the same search term:
    These metrics become decisive in these cases as the content relevancy factor is the same across all the competitors.
    Example: Multiple websites have written a (similar) review for the same product – Google will probably rank the faster page higher.

One more thing to keep in mind is that the ranking applies by device type:

  • Mobile (including AMP)
  • Desktop

Mobile rankings are solely based on mobile data, and the same applies to desktop rankings.

Although the page experience signals will impact the search rankings, these are not the be-all and end-all ranking factors.

Google made it clear that page experience is only one of several (almost 200!) factors used to determine the rankings.

In fact, John Mueller was quick to point out that “a good page experience doesn’t override having great relevant content.”

Unless your website is particularly poor at these metrics, you shouldn’t see a dramatic impact.

How Do I Check My Core Web Vitals?

Before we show exactly how you can check your site’s Core Web Vitals, let’s take a look at how Google evaluates them.

The data used to evaluate these metrics comes in one of two ways:

  1. Field Data: Field Data is measured on real users interacting with your web page. It reflects the true performance of the site in different user scenarios.
    The Field Data for Core Web Vitals comes from the “Chrome User Experience Report (CrUX).”
    CrUX data reflects how real-world Chrome users experience the web, aggregated over the course of a month.
  2. Lab Data: Lab Data is simulated through bots and algorithms in a controlled environment.
    As the data based on lab simulations isn’t used in the measurement of Core Web Vitals, we won’t be interested in that here.

Google then performs the desired calculations on this Field Data (CrUX) and assesses whether the page passes the Core Web Vitals threshold.


If all of that sounded overwhelming, don’t worry!

The key takeaway is that we need to evaluate our metrics on the same data that Google uses, i.e., the CrUX.

How to do that?

It’s much easier than it sounds.

We’ll go over the three most effective tools to check your Core Web Vitals scores: Search Console, PageSpeed Insights, and Lighthouse.

1. Google Search Console

You can find the site-wide Core Web Vitals report in the Search Console itself.

Under the ‘Experience’ section (moved from ‘Enhancements’) in your Search Console, you’ll see the Core Web Vitals as well as the Page Experience reports for your site.

The report labels each URL based upon its scores: Good, Need Improvement, or Poor.

Straightforward, isn’t it?

The only caveat is that the websites subject to very little traffic or insufficient time to gather data will be omitted. Such sites need to give Google a little more time for the collection of data.

2. PageSpeed Insights

PageSpeed Insights is another super-easy way to check your Core Web Vitals report.

This tool reports you on both the field data and lab data, as well as the performance on both mobile and desktop devices.

The best part is that PageSpeed Insights can work on a per-page level, so you can pinpoint the pages that do not meet the quality thresholds.

It also gives you detailed diagnostics and improvement opportunities so you can start working on the metrics right away!

3. Lighthouse

Lighthouse is a website auditing tool that you can run inside Chrome DevTools or as a Chrome/Firefox plugin.

It measures the performance, accessibility, and several other user-experience parameters in a lab environment.

The latest release of Lighthouse (6.0) includes two of the three Core Web Vitals: LCP and CLS, apart from other audits and metrics.

You can’t assess FID based on lab testing, and Lighthouse provides a new metric called Total Blocking Time (TBT) that somewhat correlates with FID.


That’s all you need to know about Core Web Vitals.

You don’t have to be a technical SEO expert or performance guru to monitor and improve your Core Web Vitals metrics.

Following the actionable insights provided in Search Console or other auditing tools, you can set yourself up to provide the best possible web experience to the users as well as Google’s ranking system.