CLS (Cumulative Layout Shift)

Each time a visible element shifts without user interaction, that shift's share (relative to the page size) is added to this number; under 0.1 is good and beyond 0.25 is poor. Unlike the other metrics on this dashboard, CLS has no time unit — it's a relative score.

This metric casts a direct shadow over user peace of mind, conversion rate, and brand credibility. When CLS is high, users face a sudden jump of elements at the exact moment they mean to click a button or read an article; the fallout from that unwanted jump is an accidental click on an unrelated ad, lost focus, and ultimately an angry tab close.

From a business perspective, this frustrating experience means wasted marketing campaigns, lost potential customers, and a sharp drop in conversion rate. Search engines also count this metric as a key factor in user-experience quality; so taming unwanted layout shifts both boosts sales and engagement, and protects the site's SEO standing in Google's results.