What is CLS by server distance
CLS by server distance shows Cumulative Layout Shift (CLS) based on how far the user is from the server that delivered the page. This lens helps you understand whether geographic distance and network instability contribute to layout shifts.
Only distance groups with actual traffic during the selected timeframe will appear in the view.
While layout shifts are mostly frontend-related, distant users may face delayed asset loading due to network lag. When styles, fonts, or images load too late, they can push visible content around, causing layout instability.
Healthy CLS by server distance sample
If CLS is consistently green across all distance bands (Low, Mid, High), your site is serving predictable, stable layouts globally. This usually indicates good use of CDNs and well-structured content delivery.
Unhealthy CLS by server distance sample
In the example below, users located farther from the server experience worse layout shifts. This may be due to:
Fonts or CSS arriving late over slow connections
Missing preload hints for critical assets
No edge serving for layout-critical resources
CDN misconfigurations or cache misses
This is especially impactful for global websites targeting audiences beyond North America or Europe.
Resolving unhealthy CLS by server distance
Go-to action plan to resolve an unhealthy CLS by server distance:
Ask Uxi to analyze your CLS by server distance values and suggest improvements
Use Filters to focus on affected regions, then cross-reference with other CLS lenses (like connection type or device).
Simulate CLS of the suspected lens to see if fixing it will resolve the CLS by server distance. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by server distance values
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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