How to Optimize Cumulative Layout Shift (CLS)?

Apr 29, 2021
Optimize Cumulative Layout Shift (CLS) metrics

Cumulative Layout Shift is one of the three essential metrics of Core Web Vitals.

Cumulative Layout Shift Optimization helps you eliminate shifters on your site and improve your users' experience.

Remember, the worse the user experience on your site, the worse the SEO performance you get and fewer leads.

We're sure that you, as a user, have encountered the Cumulative Layout Shift nuisance too, when you enter a site. and want to open a video, but click on an ad or something else because the site has shifted. This irritates everyone.

It is precise to get rid of such an annoying and unpleasant user experience that you should read this blog. The Drupal development firm will show you what is Cumulative Layout Shift optimization and why you should think about it.

What is cumulative layout shift (CLS)?

Cumulative Layout Shift (CLS) is a metric measuring the level of layout shifts of content, videos, buttons, images, forms on your site. It shows how stable the content of your site is when loaded and displayed on various devices.

If a user loads your site and the layout moves up, down, right or left, this is very bad, and the CLS will be high.

Google has focused on providing the most convenient user experience and is scrupulous about which sites to show in search. Therefore, Cumulative Layout Shift (CLS) optimization is needed if your site has problems with this and does not meet the CLS shifting standards.

What Are Good and Bad CLS scores?

The higher the CLS score, the worse it is for your site, and the faster you need to reduce Cumulative Layout Shift (CLS). Here are the official CLS scores according to Google.

  • Good CLS score - below 0.1
  • CLS score needs improvement - between 0.1 and 0.25
  • Bad CLS score - above 0.25
 CLS scores

Does CLS score affect your SEO?

Yes! Starting May 2021, Cumulative Layout Shift will be one of the leading Web Vitals metrics. It will affect your SEO, traffic, and more. 

Prepare in advance and optimize Cumulative Layout Shift, so you don't suffer from SEO problems later. Improve CLS to please search engines and give your users a hassle-free website experience.

How is Cumulative Layout Shift calculated?

To defeat an enemy, you must know them. In this case, you need to know your CLS level for today to see if you need to optimize the Cumulative Layout Shift. To get actual CLS values, measure them both in a lab and during fundamental interactions.

How to measure CLS in a “lab”?

The lab does not mean that you have to go to some special laboratory, just that before you get the CLS metrics, you simulate your site's interaction using a range of tools. You can use tools to measure CLS in a “lab”:

How to measure CLS in a “lab”?

How to measure CLS using Real User Data

Real User Data means that you get data based on real user interaction data with your site. This data shows you the full picture and lets you compare it with the data you got with lab measure. To measure CLS in Real User Data, you can use: 

How to measure CLS using Real User Data

How can you prevent and improve the CLS?

Include width and height elements

Get in the habit of always specifying "width" and "height" attributes for images, videos, miscellaneous content, ad units, and other elements. 

This will help avoid incorrect arrangement of elements on the screens of various devices. This tactic reserves the suitable space for the elements and keeps them from being misplaced.

Preload your fonts

You are definitely using at least one Google font or font from another source. Their downloads affect the CLS. This means that before loading them, it will take a few seconds and the user will see a blank space. To avoid this, you can use font: display.

To solve this problem, preload your fonts, host the fonts locally, set up aggressive caching, or use CDN

Reserve space for ad contents

This will help you prevent layout shifts. To optimize Cumulative Layout Shift, you should pre-allocate as much space for the ad as possible. It is better to have white space than a shift.

If you don't, then users will click on your ad, not on what they meant to click, and they will be angry. This will affect your bounce rate and CLS scores.

Display dynamic content below the main content

Each site contains dynamic content. These can be CTAs, notifications, bars, and many many others. Often, such elements can cause changes and shifts on your site.

We do not say not to use dynamic content at all, just place it below the main content instead of above it. This helps you to avoid unpredictable shifting.

Ask specialists to help your site

Cumulative Layout Shift Optimization is not an easy thing to do. You need to have special CMS knowledge to fix Cumulative Layout Shift (CLS), and a comprehensive understanding of all the processes to set up and fix the site properly because everything is interconnected. Alternatively, you can get help from web developers.

Fix Cumulative Layout Shift (CLS) with the Drudesk

The easiest way to optimize Cumulative Layout Shift is to contact website support experts, especially if you don't have deep coding skills yet.

Optimizing the CLS score is not an easy process — it takes time to find the problem and solve it. However, don't neglect Cumulative Layout Shift (CLS) as it affects the user experience on your site, click-through rates, conversions, and most importantly, your SEO!

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