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Mastering CLS Optimization: Key Tips and Techniques for Website Speed
📖 4 min read- Authors
- Name
- T.O.D.
- @TODSocial
How to Improve Cumulative Layout Shift (CLS)
Cumulative Layout Shift (CLS) is an important metric that measures the visual stability of a website. A high CLS score can result in frustration, confusion, and even lead to users abandoning a website. In this blog post, we will discuss 10 tips and techniques to improve CLS and provide a better user experience.
1. Use a Clear Content Hierarchy
Using a clear content hierarchy can help improve CLS by ensuring that content is loaded in the correct order. This can help reduce unexpected layout shifts and improve the user experience. Make sure to use proper heading tags, prioritize above-the-fold content, and avoid using inline styles.
2. Optimize Images and Media
Large images and media files can be a significant contributor to layout shift. To improve CLS, optimize images and media by compressing files, using responsive images, and lazy-loading images and videos.
3. Minimize Render-Blocking Resources
Render-blocking resources can cause delays in page load times, which can contribute to layout shift. To minimize render-blocking resources, prioritize critical CSS, defer JavaScript, and use asynchronous loading for third-party scripts.
4. Preload Key Resources
Preloading key resources can help improve CLS by ensuring that important resources are loaded as quickly as possible. This can help reduce delays and improve page load times. Make sure to preload critical fonts, images, and scripts.
5. Avoid Intrinsic Sizing
Intrinsic sizing can cause unexpected layout shifts, especially when loading images or media. To avoid intrinsic sizing, use aspect ratios and set explicit dimensions for images and media.
6. Test and Monitor Performance
Testing and monitoring performance can help identify issues that can contribute to layout shift. Use tools such as Lighthouse and WebPageTest to identify performance issues and monitor performance over time.
7. Avoid Third-Party Content
Third-party content can be a significant contributor to layout shift. Make sure to only use third-party content that is necessary for your website, and try to avoid using third-party content that loads slowly or is unreliable.
8. Use CSS Animation
CSS animation can be used to create visually appealing and interactive content without causing unexpected layout shifts. By using CSS animation instead of JavaScript animation, you can reduce the likelihood of unexpected layout shifts and improve CLS.
9. Optimize Web Fonts
Web fonts can be a major contributor to layout shift. Make sure to optimize web fonts for web and use appropriate font loading techniques, such as using the "font-display" property to specify how fonts should be displayed before they are loaded.
10. Use a Content Delivery Network (CDN)
A content delivery network (CDN) can help improve CLS by delivering content from a server that is geographically closer to the user. This can help reduce latency and improve page load times, which can reduce the likelihood of unexpected layout shifts.
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Conclusion
To improve CLS, use a clear content hierarchy, optimize images and media, minimize render-blocking resources, preload key resources, avoid intrinsic sizing, test and monitor performance, avoid third-party content, use CSS animation, optimize web fonts, and use a content delivery network (CDN). By following these tips and techniques, you can ensure that your website provides a stable and predictable user experience, and avoid the negative impacts of a high CLS score.