Cumulative Layout Shift (CLS)

Cumulative Layout Shift (CLS) measures visual stability during page load. It quantifies unexpected shifts in elements, impacting user experience and SEO performance, part of Core Web Vitals.

Cumulative Layout Shift (CLS) is a metric used to measure the visual stability of a webpage during its lifecycle. It refers to how much a webpage’s elements unexpectedly shift or move while the page is loading or after it has loaded, affecting the user experience. CLS is one of the three key metrics in Google’s Core Web Vitals, which evaluates a page’s overall user experience, with a specific focus on visual stability, interactivity, and loading performance.

In simple terms, CLS measures how much the layout of a page “shifts” or moves around while a visitor is interacting with it. A high CLS score indicates a page that has a lot of visual instability, which can lead to a frustrating user experience, especially when text, images, or interactive elements move unexpectedly, causing users to click on the wrong button or lose their place on the page.