Understanding Content Layout Shift (CLS) and How to Fix It for Seamless User Experience

As web developers, we strive to create engaging and user-friendly websites that provide a delightful experience to visitors. However, one common issue that can frustrate users and harm a website's usability is Content Layout Shift (CLS). In this blog, we will explore what CLS is, its impact on user experience and SEO, and most importantly, how to fix it to ensure a smooth and visually stable browsing experience for all users.

What is Content Layout Shift (CLS)?

Content Layout Shift (CLS) refers to the unexpected movement of web page content during its loading process. It occurs when elements on a page, such as images, videos, or ads, don't have a predefined size or don't reserve enough space, causing the content below them to shift or reflow as they load. CLS can lead to buttons being moved, text jumping, or links being displaced, which can be confusing and frustrating for users trying to interact with the page.

Why is CLS a Concern?

Content Layout Shift is not only an annoyance for users but also has serious implications for your website's performance. Google considers CLS as one of the core Web Vitals for measuring user experience, and it directly impacts your website's search engine ranking. Websites with a high CLS score may be ranked lower in search results, affecting organic traffic and user engagement.

Fixing Content Layout Shift: Best Practices

Here are some effective strategies to fix Content Layout Shift and improve the overall stability of your web pages:

1. Set Dimensions for Media Elements: Ensure that all images, videos, and iframes have explicit dimensions specified in the HTML or CSS. This allows the browser to allocate sufficient space for these elements during page loading, preventing sudden layout shifts.

2. Use Aspect Ratio Boxes for Images and Videos: Instead of setting fixed widths and heights for media elements, use aspect ratio boxes with CSS. This approach maintains the element's aspect ratio while allowing it to adapt to different screen sizes without causing layout shifts.

3. Defer the Loading of Ads and Third-Party Content: Load ads and third-party content using asynchronous or deferred loading techniques. This way, your main content will load first, reducing the chances of unexpected shifts caused by late-loading ads.

4. Reserve Space for Ads and Embedded Content: If your website displays ads or embedded content, reserve space for them in the layout, even if the actual content hasn't loaded yet. You can use CSS with display: hidden or visibility: hidden to hide the content until it's fully loaded.

5. Lazy Load Images and Videos: Lazy loading images and videos allows them to load only when they are about to enter the user's viewport. This prevents them from pushing down the content below and helps improve CLS significantly.

6. Optimize Font Loading: Optimize the loading of web fonts to avoid layout shifts caused by delayed font rendering. Consider using font-display: swap in your CSS to display fallback fonts until custom fonts are fully loaded.

7. Test and Monitor Your Website: Regularly test your website using tools like Google PageSpeed Insights, Lighthouse, or WebPageTest to identify CLS issues and other performance bottlenecks. Monitor your website's performance over time to ensure continuous improvement.

Conclusion

Content Layout Shift can have a significant impact on user experience and website performance. By following the best practices mentioned above, you can minimize CLS, create a visually stable browsing experience, and improve your website's search engine ranking. Prioritizing a seamless user experience not only benefits your users but also contributes to the success of your website and business in the long run. Happy optimizing!