What is CLS by device CPU cores
CLS by device CPU cores shows Cumulative Layout Shift (CLS) values across different CPU core counts (e.g. 4 cores, 8 cores). This breakdown helps you spot if users on less powerful devices are more likely to experience layout jumps.
Only devices with traffic during the selected period are included.
Devices with fewer CPU cores can struggle to process complex layout updates or animations, increasing the chance of layout shifts — especially during page load or scroll.
Healthy CLS by device CPU cores sample
If all cores are green, layout stability is solid across devices. Even if some cores are slightly slower, avoid any yellows or reds to stay within a healthy range.
Unhealthy CLS by device CPU cores sample
If users with 4-core devices (often older or mid-range phones) show red or yellow, their layout is visibly shifting. This can make the experience feel jumpy or untrustworthy.
Resolving unhealthy CLS by device CPU cores
Go-to action plan to resolve an unhealthy CLS by device CPU cores:
Ask Uxi to analyze your CLS by device CPU cores values and suggest improvements
Use Filters to the affected core group and review other CLS breakdowns with high pageviews and bad scores.
Simulate CLS of the suspected breakdown to see if fixing it will resolve the CLS by device CPU cores. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by device CPU cores values
Once you’ve improved CLS, set an alert to be the first to know if it starts worsening again.
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