Suggest an editImprove this articleRefine the answer for “What is CLS (Cumulative Layout Shift)?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**CLS (Cumulative Layout Shift)** is a metric that measures **how much elements on a page shift while it loads**. **Key point:** the target is below 0.1; a score above 0.25 is considered poor and signals visual instability on the page.Shown above the full answer for quick recall.Answer (EN)Image**CLS (Cumulative Layout Shift)** is a metric that measures **how much elements on a page shift while it loads**. ### What it looks like: - You're reading text, and suddenly everything shifts down because an ad loaded. - You click a button, but right at that moment it "ran away", and you clicked the wrong spot. That's a layout shift: the interface jumping around. ### What counts: Every **sudden shift of a visible element**, for example, when text, buttons, or images move **without any user interaction**. ### How it's calculated: CLS is the sum of all such shifts over the page's lifetime. - The bigger and more frequent the shifts, the higher the score. ### The benchmark: - **Good:** below **0.1** - **Acceptable:** 0.1-0.25 - **Poor:** more than 0.25 ### Causes of a high CLS: - Images without specified dimensions - Fonts loaded asynchronously - Blocks that appear late (banners, iframes) - Animations that shift the layout --- **Conclusion:** CLS is about **visual stability**. A good site doesn't jitter. Everything stays put, the way users expect.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.