What is CLS by browser language
CLS by browser language shows Cumulative Layout Shift (CLS) segmented by the user’s browser language preference — such as en-US, fr-FR, es, or de. This helps uncover whether certain localized versions of your site cause more layout instability than others.
Only browser languages with traffic during the selected period are shown.
While browser language doesn’t guarantee geographic location, it often aligns with region-specific content, translations, or third-party scripts that can affect layout performance.
Localized experiences can unintentionally introduce layout shifts due to:
Differences in text length or font fallback between languages
Improperly styled translations that expand layout containers
Language-specific banners, notices, or embedded content
Dynamic rendering or personalization logic for certain regions
These variations can impact the stability of the page as it loads, especially for first-time visits.
Healthy CLS by browser language sample
If all major languages show green CLS values, your site is delivering a stable experience regardless of localization. Some minor variation is expected — for example, German or Finnish may produce longer words that stretch layouts. But no language should consistently trigger layout shifts.
Unhealthy CLS by browser language sample
If one or more languages are showing high CLS, you may be facing:
Translated text breaking out of containers (e.g. buttons, headers)
Dynamic region-specific content (e.g. cookie notices or promotions) loading late and pushing content
Inline styles not properly scoped for RTL (right-to-left) languages like Arabic or Hebrew
Unoptimized fallback fonts causing layout jank in localized versions
Resolving unhealthy CLS by browser language
Go-to action plan to resolve an unhealthy CLS by browser language:
Ask Uxi to analyze your CLS by browser language values and suggest improvements
Use Filters to isolate the problematic language group and compare page templates or elements.
Simulate CLS of the suspected lens to see if fixing it will resolve the CLS by browser language. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by browser language values
Once you’ve improved CLS, set an alert to be the first to know if it starts worsening again.
Try it yourself
Discover how your website performs with real user data.