Code
Audit page performance
An LCP breakdown, what is blocking, and the fixes ordered by milliseconds saved.
Fill it in
What to trace.
Which profile.
In milliseconds, so the list can be ordered.
Your prompt
Audit [the page] on Mobile on 4G. Break LCP into its four phases: time to first byte, resource load delay, resource load time, and render delay. A single LCP number tells you nothing about what to fix, and the phase breakdown usually shows the problem is not the image everyone assumed. Find what BLOCKS. Render-blocking CSS, synchronous scripts in the head, and fonts without a display strategy account for most of the difference between a fast site and a slow one, and none of them show up in a bundle-size report. Check the third parties separately and total them. That number is usually the uncomfortable finding. Estimate each fix in milliseconds saved, so the list can be ordered by value rather than by how easy it is to describe.
Use Audit page performanceOpens with everything above already filled in.
Why this works
A single LCP number tells you nothing about what to fix, and the phase breakdown usually shows the problem is not the image everyone assumed. This also totals the third parties separately, which is normally the uncomfortable finding.