Cumulative Layout Shift: Crawl Audit check 74

Short answer: Cumulative Layout Shift (CLS) scores how much the page moves while someone is reading it: the button that jumps just as you tap it, the text pushed down by a late image. It's a Core Web Vital. Check 74 passes at 0.1 or less, warns up to 0.25 and fails above that.

What Crawl Audit checks

• Full report: real-user CLS from the Chrome UX Report when available, otherwise Lighthouse's lab figure.
• Free check: an estimate from the share of images missing width and height (check 81). A page with no images is estimated at 0.02.
• Pass: 0.1 or less. Warning: up to 0.25. Fail: over 0.25.

What Google says

• web.dev: "CLS is a measure of the largest burst of layout shift scores for every unexpected layout shift that occurs during the entire lifecycle of a page."
• "Good CLS values are 0.1 or less. Poor values are greater than 0.25."

On devmarde.com

On 3 October, PageSpeed Insights measured our homepage CLS at 0.014 on mobile (lab test). All seven images on it have width and height set.

What causes shifts, and the fixes

• Images and videos without dimensions. web.dev: "Always include width and height size attributes on your images and video elements. Alternatively, reserve the required space with CSS aspect-ratio or similar."
• Adverts, embeds and banners that load late and push content down. Give their container a fixed height.
• Web fonts that swap in at a different size. See check 98.
• Content added above what's already there, such as a cookie bar or promo strip at the top. Put it in reserved space, or overlay it.

Sources

• web.dev, Cumulative Layout Shift (CLS) and Optimize Cumulative Layout Shift (updated 7 February 2025), checked 3 October 2026.