What is CLS by visitor ID
CLS by visitor ID lists anonymized visitor IDs and the Cumulative Layout Shift (CLS) each experienced across visits in the selected period—color-coded by status. It reveals whether the same person repeatedly encounters layout movement.
Cumulative Layout Shift (CLS) measures unexpected layout movement while the page is visible.
CLS by visitor ID sample
Mostly green IDs indicate that banners, ads, fonts, and dynamic modules remain stable for both first-time and returning visitors.
Unhealthy CLS by visitor ID
Clusters of yellow/red IDs suggest repeat instability—often from late-loading promos, recommendations, or iframes that push content during subsequent visits or specific logged-in states.
Resolving unhealthy CLS by visitor ID
Go-to action plan to resolve an unhealthy CLS by visitor ID:
Ask Uxi to analyze your CLS by visitor ID values and suggest improvements
Use Filters to isolate IDs with high CLS and map which modules shift (ads, badges, totals).
Simulate CLS of the suspected breakdown to see if fixing it will resolve the CLS by visitor ID. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by visitor ID values
Once you’ve improved CLS, set an alert to be the first to know if it starts worsening again.
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