Core Web Vitals: How to optimize your site’s performance

If you gravitate in the world of SEO ( search engine optimization)  you have probably heard of new positioning factors that are about to be evaluated by the Google algorithm: the  Core Web Vitals . 

After Google first announced they would hit the scene in May 2021,  their rollout date was recently pushed back  and they are expected to roll out from mid-June (2021).

Core  Web Vitals , which can be translated as "essential web signals", are measures that indicate  the performance of your pages based on actual usage data . These will aim to evaluate the web pages and assign them a score according to:

• their speed,
• their responsiveness,
• their visual stability.

This new update to its positioning algorithm aims to improve the way Google analyzes the overall experience offered by websites. The  Core Web Vitals  therefore join the UX signals, already weighed by the search engine:

• mobile adaptability ;
• safe browsing ;
• the use of  HTTPS ;
• compliance with  best practices for interstitial windows .
  

As mentioned earlier, Google has already identified the three main metrics that will be evaluated as part of the "essential web signals" and will help score a site's page experience.

LARGEST CONTENTFUL PAINT (LCP)

The first web performance metric is the  Largest Contentful Paint  (LCP). The latter sheds light on the time it takes to load the largest visible element (usually the main content of the page). When we talk about the largest visible element, we are often talking about an image or a video, but it is also possible that it is a text element.

That said, the format of the main content does not matter. What really matters is that it is loaded quickly. According to the recommendations issued by Google, an LCP of 2.5 seconds or less should ideally be observed.  

FIRST INPUT DELAY (FID)

The second metric gauged by the search engine is the  First Input Delay  (FID), or the time elapsed between a user's first action and the browser's response. In other words, the time taken for a page to be responsive. This value is especially important on pages where a user action, such as clicking a link or pressing a button, is expected.

What we try to evaluate with the FID is the responsiveness of the web page. Also according to Google, the  ideal FID is 100 ms or less .

CUMULATIVE LAYOUT SHIFT (CLS)

The third metric to keep in mind is the  Cumulative Layout Shift  (CLS). Google defines it as  the sum total of scores for each unexpected layout mismatch that occurred during the life of the page  . To keep things simple, here are four examples of visual content on a page that can change layouts unexpectedly and affect CLS: 

• a dimensionless image;
•  dimensionless ad and  iframe integrations;
• dynamically injected content (banners and forms modifying the rest of the content);
• fonts causing FOUT (flash of unstyled text) or FOIT (flash of invisible text).

The  Cumulative Layout Shift  allows the search engine to assess the visual stability of web pages. According to Google, a web page should ideally get a  CLS score of less than 0.1 . 

Now that you know the three main performance measures listed among the Core Web Vitals, as well as what they allow to observe, you will now need to analyze them to optimize the efficiency of your web pages. A variety of tools are made available to users, but we have selected for you the three that we have deemed to be the most important.

THE GOOGLE SEARCH CONSOLE

To help webmasters track the performance of their web pages through essential signals analysis, Google recently added a new report,  Core Web Stats , which can be accessed from the  On-Page Experience section  of the  Google Search Console. .  

In this report, you will find your indexed URLs in three categories: 

• Good
• Improvement needed
• Poor 

It is important to note that the Google Search Console report will not offer you optimization recommendations. On the other hand, there is a link to  PageSpeed ​​Insights , which allows you to test the selected page. It is by virtue of this tool that you will be able to identify concrete solutions.

THE GOOGLE PAGE SPEED ​​INSIGHT REPORT

Sites and web pages do not always face the same problems. It is therefore difficult to make general recommendations that work every time. That said, here are some optimization ideas that apply to many sites:

• image optimization;
• use of browser cache;
• minify HTML, CSS and JavaScript resources;
• optimization of JavaScript and CSS resources.

If these tips don't apply to your situation, we suggest prioritizing your needs and starting by tackling the issues that affect the most pages or the most important pages in your website.

LIGHTHOUSE, CHROME DEV EXTENSION. TOOLS & THE CRUX API (MORE TECHNICAL)

For those who are interested in the technical aspect of the performance of their site and its pages, other tools are available to you to deepen your analysis and observe with precision the effectiveness of your platform in relation to the  Core Web Vitals  including, among others, the following:  

• Lighthouse ,
• Chrome DevTools ,
• Crux API .

Finally,  Web Vitals , a new extension for the Chrome browser available in the Chrome Web Store, was also created expressly to measure the speed, responsiveness and visual stability of your pages in real time.

In conclusion, it is important to keep an eye on the performance of your site and its pages with the  Core Web Vitals , since these will very soon become positioning factors of the utmost importance. As we have seen over the past few years, Google is relying more and more on the user experience when updating its algorithm. The essential web signals will therefore very soon appear as essential data in the analysis of the performance of your website. 

That being said, although a solid technical base is essential for good SEO, the best way to position yourself favorably in search results is to create and offer unique content tailored to its users, meeting their needs. , their problems and their questions.