What is the dual value of optimizing CLS (Cumulative Layout Shift) for user experience and SEO?

When website optimization addresses Cumulative Layout Shift (CLS), it can significantly enhance both user experience and search engine performance simultaneously, which is its core dual value. CLS measures the unexpected displacement of elements during page loading, with lower values (ideally <0.1) indicating stronger layout stability. From the perspective of user experience, low CLS prevents users from making erroneous operations (such as clicking the wrong button) due to sudden element movements and reduces the sense of reading interruption. This is particularly true for e-commerce and information websites, where it can increase user dwell time and interaction willingness. From an SEO standpoint, CLS is one of Google's Core Web Vitals metrics. Optimization typically strengthens a page's competitiveness in search results, especially for industries relying on user interaction (such as retail and services), where good layout stability may indirectly boost conversion rates. It is recommended to reduce CLS by specifying image/video dimensions, avoiding dynamic content insertion, using skeleton screens, etc., which not only improves user retention but also lays the foundation for SEO performance.