Cumulative Layout Shift (CLS) is a site experience statistic that measures how often your site’s pages move unexpectedly.
A low CLS score has an influence on your website’s search engine optimization even if other factors also affect user experience, such as other site components. (SEO). Therefore, knowing what CLS is and how to get a good CLS score aids in improving your website’s functionality as a whole.
This article will go over the many methods for calculating a CLS score. At the conclusion of this essay, we will also explain what factors impact it and address some frequently asked questions regarding CLS.
By calculating the total amount of unexpected layout changes on a page, Cumulative Layout Shift measures the visual stability of web pages. When a visible element’s position or size changes and the surrounding content follows, this is known as a layout shift.
Being that it has an impact on the functionality and user experience of the website, cumulative layout shift is a ranking factor in Google. A website that does not adhere to Google’s standards may be penalized. It is one of the Core Web Vitals indicators.
A low CLS score implies that a website is untrustworthy, which may drive visitors to abandon it sooner. As a result, optimizing your website for a high CLS score is a critical component of a successful SEO strategy.
A website with a high CLS score has a significant number of unexpected layout changes. A wholly static page, on the other hand, can receive a score of zero.
To assist site owners in measuring and raising their CLS scores, Google has established a standard for all Core Web Vitals metrics:
Varying online pages and screens on a website may have varying CLS ratings. Layout shifts on mobile screens have a more significant impact on mobile user experiences.
Here are two popular methods to do a Cumulative Layout Shift test:
There is no superior technique, as using both will offer more trustworthy statistics on the performance of your website. Google provides many free tools to help you measure the CLS of your website.
The outcome of measuring CLS in a lab only takes into consideration a tiny number of potential circumstances. The majority of browser development tools include a mechanism to determine a web page’s CLS score, frequently providing a rectangle overlay indicating the problematic areas.
Here are the steps to measure CLS using Google Chrome’s Developer Tools:
Be aware that different visual components representing layout changes may result in many Layout Shift tabs with varying ratings. To determine which component is creating the problem on your website, click on each tab.
The other way to analyze your website’s overall performance is by measuring real user interactions using the Chrome User Experience Report (CrUX) as the primary source of data.
PageSpeed Insights is a well-liked tool for measuring the data from your actual users. The procedures for using PageSpeed Insights to determine a web page’s CLS score are listed below.
Other popular tools to help measure CLS in the field are BigQuery and Looker Studio.
Some factors to consider if a website has a poor CLS score include:
These activities frequently wait for a network response before uploading items, resulting in more unexpected layout adjustments.
The precise components that might lead to a problem with layout shifting can be identified using the techniques used to calculate a web page’s CLS score.
The unreliable elements on the Layout Shift page, for instance, are shown in the Performance section of a browser’s developer tools.
To assess user experience, cumulative layout shift evaluates unanticipated changes in the user viewport area. Additionally, CLS has a big influence on your SEO because it affects Google rankings.
A website with outstanding visual stability has a CLS value of less than 0.1, while anything higher than 0.25 suggests poor performance. We demonstrated two approaches for measuring CLS: in the lab and the field. While either approach can be used, utilizing both yields more trustworthy information about website performance. for more follow us on Twitter.