CLS (Cumulative Layout Shift)

DefinitionCLS measures how much visible content unexpectedly moves while a page is in use. Good is 0.1 or less.

Layout shifts happen when images or embeds load without reserved space, when fonts swap, or when banners are injected above content. Setting width and height on media and reserving space for late content are the usual fixes.

Learn it step by step

• Monitor Core Web Vitals (SEO audits)

Related terms

• Core Web Vitals: Core Web Vitals are Google's three user-experience metrics for loading (LCP), responsiveness (INP) and visual stability (CLS), measured on real visits.
• LCP (Largest Contentful Paint): LCP measures how long it takes for the largest image or text block in the viewport to appear. Good is 2.5 seconds or less.
• INP (Interaction to Next Paint): INP measures how quickly a page responds visually to clicks, taps and key presses across a visit. Good is 200 milliseconds or less.