What is CLS by shopping cart
CLS by shopping cart shows how Cumulative Layout Shift (CLS) differs depending on whether users have items in their cart during a page visit.
This lens is especially useful for ecommerce sites, where cart-based personalization, banners, or scripts can shift layout unexpectedly — particularly for returning or high-intent users.
Healthy CLS by shopping cart sample
In a healthy setup:
Both with and without cart items show low CLS
Cart previews, headers, or dynamic elements load in a reserved space without pushing content
Personalization or upsell logic doesn’t cause jank
This is ideal — users closer to checkout aren’t being disrupted by shifting layouts, and new visitors experience the same visual stability.
Unhealthy CLS by shopping cart sample
If “with items in cart” has worse CLS:
Cart previews or banners are injected late, shifting content downward
Totals or upsells load after layout has stabilized, pushing visible content
Personalization scripts or A/B tools trigger layout shifts tied to cart logic
If “without items in cart” has worse CLS:
Your baseline template may have hidden or collapsing containers that expand unexpectedly
First-time visitors might face unstable layouts that hurt first impressions and increase bounce risk
Either case highlights a performance gap tied to the shopping journey.
Resolving unhealthy CLS by shopping cart
Go-to action plan to resolve an unhealthy CLS by shopping cart:
Ask Uxi to analyze your CLS by shopping cart values and suggest improvements
Use Filters to isolate high-shift sessions for cart vs no-cart
Simulate CLS of the suspected lens to see if fixing it will resolve the CLS by shopping cart. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by shopping cart 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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