What is LCP by third party
LCP by third party shows how different third-party scripts contribute to the Largest Contentful Paint (LCP) delays on your pages.
This lens helps you identify which external tools - such as analytics, ads, tag managers, widgets, or personalization engines - may be slowing down the critical rendering path.
Only third-party sources that were active and measurable during the selected period are listed.
LCP is the most popular vital from the Core Web Vitals and represents the loading time of the largest element on the page.
Healthy LCP by third party sample
Should you worry
In a healthy view, third parties have little to no impact on LCP. You may still see them listed, but they won’t appear in yellow or red. This means they’re likely loaded asynchronously, after the main content, or off the critical path.
A healthy setup typically uses:
Asynchronous or deferred loading strategies.
Early hints for core third parties (e.g. CDN-hosted fonts).
Lazy or conditional loading based on user interaction.
If your third-party stack is well-behaved and LCP remains green across the board, you’re good.
Unhealthy LCP by third party sample
A high-impact third party on LCP means it’s blocking or delaying the largest content from rendering — often by:
Injecting elements near the top of the page that push content down.
Loading large scripts before the main content is visible.
Forcing layout recalculations or style changes.
Blocking font loads or image rendering.
Common culprits include:
Ad networks (especially ones inserting dynamic containers).
Analytics scripts with poor defer setup.
Live chat tools loading in the head.
Tag managers that boot up other third parties too early.
If your LCP is red or yellow and a third party is consistently listed as a top contributor, it’s a strong signal something’s not being loaded optimally.
Resolving unhealthy LCP by third party
Go-to action plan to resolve an unhealthy LCP by third party:
Ask Uxi to analyze your LCP by third party values and suggest improvements.
Use Filters to isolate slow third-party combinations on key pages.
Simulate LCP of the suspected lens to see if fixing it will resolve the slow LCP by third party. If yes, this is where the resolution focus should be.
Use an automated LCP optimization tool like Navigation AI to improve your LCP by third party values.
Once you’ve improved LCP, set an alert to be the first to know if it starts worsening again.
Try it yourself
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