How Core Web Vitals Impact Website Rankings

A screenshot of a GTMetrix test result showing the highest grade and 99% website optimization.

If you haven’t heard yet about the recent update to Google’s algorithm called Core Web Vitals, this is a must-read for website owners. Core Web Vitals are the new page loading speed and user experience metrics that officially became part of Google search ranking signals in May 2021. Google announced the arrival of these search signals in November 2020.

These Core Web Vitals metrics have a significant impact on the way a site will rank in search results. Site owners need to know about Core Web Vitals because they also contribute towards Google’s page experience score. This metric is weighed more heavily than all previously known SEO and site engagement metrics.

Why Are Core Web Vitals Important?

For Google, it is all about the user and user expectations. Google wants to ensure that everyone gets the best possible search result for their search intent (the information they are looking for), combined with the best user experience. Consider these statistics related to loading speed:

  • As described by Google, people are around 24% less likely to abandon a page with a fast loading time, as opposed to a slow-loading page.
  • If page load time increases from one second to three seconds, the bounce rate increases by 32%.
  • If the load time increases to six seconds, the bounce rate can more than double (106%).

By introducing Core Web Vitals, Google found a way to measure relevant user and page experience factors on each of a site’s web pages. Sites that meet all the web vitals are labeled as “Google Core Web Vitals verified.”

Here is an example of our website exceeding the Core web vital standards for a mobile device.

A screenshot of a GTMetrix test result showing the highest grade and 99% website optimization.

Site owners that optimize for the 3 Google Core Web Vitals, as shown above, will see many benefits in Google search such as:

  • Higher search rankings
  • More indexed keywords
  • Increased web traffic and page views
  • Lower bounce rate
  • Better user experience
  • Increased conversion rates

Simply put, the Core Web Vitals directly influence the long-term success of your website. If all else is equal (two websites having high-quality content, no pop ups, implementing safe browsing principles), page experience signals are a tie-breaker of sorts. The website that has a better Core Web Vitals score ranks higher and gathers more clicks from organic search in search engine results.

Core Web Vitals Metrics

Google Core Web Vitals are comprised of three factors. They include:

  • Largest Contentful Paint
  • First Input Delay
  • Cumulative Layout Shift

Largest Contentful Paint (LCP)

The Largest Contentful Paint or LCP, measures the loading speed of the most prominent element on the user’s screen. Page elements can be the largest image, content element, video, or a large font. LCP represents the speed at which the website loads from the device the user happens to be visiting your website, also called the perceived loading speed of a page.

Google sorts web pages into three groups based on their LCP performance:

  • Good – LCP under 2.5 seconds
  • Needs Improvement – LCP between 2.5 and 4 seconds
  • Poor – LCP above 4 seconds

Your website pages should load the content for the end user within 2.5 seconds of viewing it in a browser for the first time. Anything lower than that is considered poor LCP.

Many issues can cause a low LCP score, including unused CSS, JavaScript, slow server response times, client-side rendering, or problems with other resources loading slowly. 

Improving your LCP score can be done by optimizing the website’s core elements and removing unnecessary content.

The goal is to have a high percentage of pages in the “Good” category by using best practices for loading web pages quickly (one of them being lazy loading).

First Input Delay (FID)

The First Input Delay or FID, measures how fast a user can interact with a loaded page. It represents the time between the user clicking on an interactable element (link, button, menu, text field) on a page and the result of that interaction.

Here are Google’s guidelines for FID:

  • Good – FID under 100ms  
  • Needs Improvement – FID between 100 and 300ms
  • Poor – FID over 300ms

Similar to the Largest Contentful Paint metric, the First Input Delay issues are caused by poorly optimized CSS or JavaScript.

Cumulative Layout Shift (CLS)

The third Core Web Vitals metric is called Cumulative Layout Shift or CLS, which looks at the responsiveness and visual stability of the page. If elements on your page move or shift as the page loads, the user experience can suffer as the element may not be aligned correctly and possibly not function at all.

Google’s minimum thresholds for CLS:

  • Good – CLS less than 0.1
  • Needs Improvement – CLS between 0.1 and 0.25
  • Poor – CLS over 0.25

Various factors can cause layout shifts, such as poorly optimized images, iframes, and ads without dimensions, overuse of third party code, and dynamic moving website elements above the fold as the website is loading.

Here is an example of the three Core Web Vital Metrics from the Google website.

A graph depicting the poor, needs improvement, and good values for the three Core Web Vital metrics.
Core Web Vitals image from Google directly.

How To Measure Your Core Web Vitals Score

There are a few ways to measure core web vitals metrics. One of which is Google’s PageSpeed Insights. The other is a tool called GT Metrix. They both offer a Core Web Vitals Report.

Google’s PageSpeed Insights

This is a free service that analyzes the Core Web Vitals of any website. It examines page load speed, website performance, and mobile-friendliness to give an overall score for each Google ranking factor on their scale from 0-100%. The tool also offers suggestions on how you can improve your site.

You can find the Google PageSpeed test here, and it looks like below:

Screenshot of the landing page of Google Page Speed Insights showing where to input your website's domain name.
You can insert your website URL in the white space just next to the black arrow and click analyze.

GTMetrix Website Test

The second and most preferred method of testing my most is a platform called GTMetrix. They show you issues and help you find out what is making your site slow. You can also test different browsers to see how they would perform on a given website, and it offers suggestions for improvements. And you can test from a number of locations around the world depending on where you primarily operate from. They have both a free and paid version.

The core tools that website owners need to know about are the Google PageSpeed Insights tool and GTMetrix. You can find GTMetrix here, and it looks like this:

The GTMetrix home page showing where to input the link of your website.

Improve Your Website

Optimizing your website for Core Web Vitals is the best thing you can do at the moment to ensure your website has a good reputation with search engines (especially Google) and is not being held back from its full potential. 

If you’re unfamiliar with website optimization and how to improve it, finding an experienced professional with a proven track record is the best way to start.

If you search for a web agency, first make sure they comply with Google’s Core Web Vitals and pass all the tests above on desktop and mobile devices before working with them. Desktop computers are also included in the Core Web Vitals Algorithm.

You can test any website using one of the methods listed above.

Remember, your website is the foundation of your business, and vital to your success online. It must meet all industry standards to reach its full potential.

To build a Strong business you need a Strong foundation!

Jason Gordon – Founder
StrongWP