Faisal Mustafa


Understanding the CLS Issue: A Crucial Factor for Ranking and Improving User Experience

In the ever-evolving world of search engine optimization (SEO), web developers and SEO experts are constantly seeking ways to enhance website performance and user experience. One important metric that plays a significant role in achieving these goals is Cumulative Layout Shift (CLS).In this blog post, I will explore what CLS is, its impact on ranking, and effective strategies to improve the CLS score.

What is CLS (Cumulative Layout Shift)?

Cumulative Layout Shift ( CLS)

Cumulative Layout Shift refers to the unexpected shifting of webpage elements during the loading process. It occurs when content on a webpage changes its position after it has already been rendered by the browser.

These shifts can be frustrating for users, causing confusion, accidental clicks, or difficulties in interacting with the website.

Importance of CLS for Ranking

CLS is not only crucial for user experience but also for search engine ranking. In May 2021, Google officially announced that CLS became a part of their Core Web Vitals, a set of metrics used to assess a website’s overall performance.

Websites with a low CLS score are more likely to rank higher in search engine result pages (SERPs), as Google aims to prioritize websites that deliver a seamless and stable user experience.

Ways to Improve the CLS Score

Now that we understand the significance of CLS, let’s delve into some effective strategies to improve your website’s CLS score:

  1. Optimize Images and Media

    Images and embedded media often cause layout shifts. To mitigate this issue, specify dimensions (width and height) for all media elements. This allows the browser to reserve the appropriate space, preventing sudden shifts when the content loads.

  2. Load Fonts and Stylesheets Early

    Ensuring that fonts and stylesheets are loaded early in the rendering process helps maintain consistency and prevents subsequent shifts. Consider implementing preloading techniques or utilizing asynchronous loading methods to minimize the impact on CLS.

  3. Avoid Dynamically Injected Content

    Content that loads dynamically, such as ads, pop-ups, or images injected by JavaScript, can cause unexpected shifts. To minimize this, reserve space for such elements during the initial rendering, so they don’t disrupt the layout when they load.

  4. Set Explicit Sizes for Ads

    If your website incorporates advertisements, ensure that ad containers have explicit dimensions. This prevents ad units from altering the layout and causing shifts when they load.

  5. Prioritize Resource Loading

    Load critical resources, such as CSS and JavaScript files, before non-critical resources. This approach ensures that the essential elements are rendered promptly, reducing the chances of CLS issues.

  6. Test and Monitor CLS Score

    Regularly monitor your website’s CLS score using tools like Google’s PageSpeed Insights, Lighthouse, or Chrome User Experience Report. Conduct thorough testing to identify problematic areas and measure the impact of implemented optimizations.


Cumulative Layout Shift is a significant factor for both user experience and search engine ranking. By optimizing your website to minimize CLS issues, you enhance user satisfaction, reduce bounce rates, and increase the likelihood of higher search engine rankings.

Implement the strategies outlined in this article to improve your CLS score and deliver a seamless browsing experience to your visitors. Remember, a visually stable website not only benefits your users but also sets you on the path to digital success.

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