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CLS by session duration

CLS by session duration without noise

Vasil Dachev avatar
Written by Vasil Dachev
Updated over a week ago


What is CLS by session duration

CLS by session duration lens measures layout stability across segments with different levels of engagement. Cumulative Layout Shift (CLS) tracks unexpected movements of elements during load — a major source of user frustration.

High MPSR users often browse multiple pages, so consistent stability is critical to maintaining trust and flow.

Healthy CLS by session duration sample

Low CLS in high-MPSR segments means returning or exploratory users are getting a polished, consistent experience. Even small layout shifts can feel more jarring during longer journeys.

Unhealthy CLS by session duration sample

If CLS increases with MPSR, deeper pages may have instability issues (e.g., injected banners, 3rd party widgets, or dynamic content shifts). Low-MPSR users with high CLS may be abandoning early due to visual disruption.

Resolving unhealthy CLS by session duration

Go-to action plan to resolve an unhealthy CLS by session duration:

  1. Ask Uxi to analyze your CLS by session duration values and suggest improvements

  2. Use Filters to identify which pages contribute to layout shifts in each session segment.

  3. Simulate CLS of the suspected lens to see if fixing it will resolve the CLS by session duration. If yes, this is where the resolution focus should be.

  4. Use an automated CLS optimization tool like Navigation AI to improve your CLS by session duration values

  5. Once you’ve improved CLS, set an alert to be the first to know if it starts worsening again.

Try it yourself

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