Glossary · Web

What is
CLS (Cumulative Layout Shift)?

Core Web Vital measuring unexpected layout shifts during page load — should be under 0.1.

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By Anish· Founder · Vedwix
·

Definition

CLS measures how much the layout shifts during page load and interaction. The most common causes: images without explicit dimensions, fonts swapping in (FOUT), late-loading ads, dynamically injected content. Fixes are usually small but tedious — set width/height on every image and reserve space for any dynamic content.

Example

A blog with ads had CLS of 0.6 (poor); reserving fixed-height ad slots dropped it to 0.05.

How Vedwix uses CLS (Cumulative Layout Shift) in client work

Fixed image dimensions and font-display strategy are checklist items every project.

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Related terms
Core Web VitalsGoogle's page experience metricsLCP (Largest Contentful Paint)Core Web Vital measuring how fast the largest visible element loads — should be under 2.5s.
More Web terms
StorybookWebServer-Side Rendering (SSR)WebStatic Site Generation (SSG)WebIncremental Static Regeneration (ISR)WebEdge RenderingWebCDNWeb

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