Suggest an editImprove this articleRefine the answer for “What is cumulative layout shift (CLS)?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**Cumulative Layout Shift (CLS)** is a metric that measures how much page elements unexpectedly shift during loading. **Key point:** a low CLS means the site is stable and predictable: nothing jumps around or disrupts the user's actions.Shown above the full answer for quick recall.Answer (EN)Image**Cumulative Layout Shift (CLS)** is a metric that measures how much page elements unexpectedly shift during loading. --- ## What causes shifts - images without specified dimensions - dynamic content that gets inserted later (for example, a banner or a button) - fonts that load later and change the width of the text - CSS animations that change the layout --- ## Example You are about to click "Place order", but at that moment a banner loads above it, the button shifts, and you accidentally click "Delete all" instead. That is a bad CLS. --- ## How it is calculated CLS = the sum of all unexpected layout shifts over the life of the page (until the content in the viewport stabilizes). --- ## Norms (per Google) - < 0.1: good - 0.1-0.25: fair > 0.25: poor --- ## Conclusion CLS shows how much the interface "jumps around" during loading. A low CLS means the site is stable and predictable, nothing jumps and nothing disrupts the user's actions.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.