What is Cumulative Layout Shift?
Also called: CLS
The short answer
Cumulative Layout Shift measures how much page content moves unexpectedly while loading; good is below 0.1.
What people say: “the page jumps”, “things move as it loads”.
Cumulative Layout Shift, explained
Set width and height on images and embeds, reserve space for ads and banners, and load fonts so text does not reflow.
Questions people ask about Cumulative Layout Shift
What is Cumulative Layout Shift?
Cumulative Layout Shift measures how much page content moves unexpectedly while loading; good is below 0.1.
Related terms
Core Web Vitals are Google's three user-experience metrics: Largest Contentful Paint for loading, Interaction to Next Paint for responsiveness and Cumulative Layout Shift for visual stability.
Web font loadingWeb font loading is how a page fetches and swaps in custom fonts; done badly it hides text or shifts layout, done well text shows immediately and swaps smoothly.
Page speedPage speed is how quickly a web page loads and becomes usable, measured by metrics like Largest Contentful Paint, Interaction to Next Paint and layout stability.
Largest Contentful PaintLargest Contentful Paint measures how long it takes for the largest visible element, usually the hero image or headline, to appear; good is 2.5 seconds or less.
Part of the Web Encyclopedia by Apex Flow Digital. Definitions are general knowledge, kept current, with no invented statistics.