What is Cumulative Layout Shift?
Cumulative Layout Shift (CLS) is a Core Web Vitals metric that measures unexpected movement of page elements while the page loads. When images, ads or embeds load late and push content down, users lose their place — a frustrating experience Google penalizes in rankings.
Why CLS matters
CLS is a ranking factor within Core Web Vitals. A page with severe layout shifts scores poorly and can drop in rankings. It also damages conversion: mis-clicks and lost reading position drive users away.
How to improve CLS
- Set explicit width and height on images and videos.
- Reserve space for ads and embeds.
- Avoid injecting content above existing content.
- Use font-display: swap to avoid text reflow.
Target
Google’s threshold is a CLS score below 0.1 on mobile and desktop. Measure it in Google Search Console and PageSpeed Insights.
Related terms
How Social SEO Team can help
We fix layout shift and other Core Web Vitals issues. See our web development services.