What is CLS by third party
CLS by third party shows how different third-party scripts contribute to layout shifts on your website. It reveals which external tools — like analytics, ads, tag managers, widgets, or personalization engines — are disrupting visual stability and causing Cumulative Layout Shift (CLS) issues.
Only third-party sources that were active and measurable during the selected period are included.
CLS is one of the Core Web Vitals and represents how visually stable a page is while it loads.
Healthy CLS by third party sample
In a healthy setup, third parties don’t trigger layout shifts. You might still see them listed, but they’ll remain green—indicating they load after the page has stabilized or outside the viewport.
A well-behaved third-party stack typically includes:
Reserved space for dynamic elements (ads, embeds, iframes).
Lazy loading that doesn’t shift visible content.
Proper dimensions declared for images, videos, and banners.
If CLS remains green despite active third parties, your integration is stable and well-optimized.
Unhealthy CLS by third party sample
A third party negatively impacting CLS is often:
Inserting banners or popups that push content after load.
Dynamically injecting DOM elements without reserved space.
Loading fonts, videos, or carousels that shift layout after initial paint.
Delaying CSS or JavaScript execution that restyles parts of the page.
Common culprits include:
Ad networks with dynamic ad placement.
Consent banners that push content downward.
Chat widgets that appear late and shift visible content.
Third-party videos or embeds loading without defined height.
If a third party appears in yellow or red repeatedly, it’s likely causing jarring layout shifts that harm UX and trust.
Resolving unhealthy CLS by third party
Go-to action plan to resolve an unhealthy CLS by third party:
Ask Uxi to analyze your CLS by third party values and suggest improvements
Use Filters to isolate pages where visual instability is most noticeable.
Simulate CLS of the suspected lens to see if fixing it will resolve the CLS by third party. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by third party values
Once you’ve improved CLS, set an alert to be the first to know if it starts worsening again.
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