CLS

Cumulative Layout Shift

Unexpected shifting of content while the page loads. For example, you're about to click a button when an ad loads and the button shifts down. This frustrates users and causes misclicks.

Thresholds

≤0.1 Good
≤0.25 Medium
>0.25 Poor
≤0.1 Good
≤0.25 Medium
>0.25 Poor

Why It Matters?

Unexpected shifts cause misclicks, form errors, and user frustration. Google considers poor CLS a serious user experience issue.

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