What is INP by LCP
INP by LCP shows how Interaction to Next Paint (INP) varies based on the Largest Contentful Paint (LCP) — revealing whether slow loading is impacting how fast the site responds once users try to engage.
LCP is a key loading metric: it tells you when the main content visibly renders. INP captures responsiveness: how quickly the page reacts when users interact.
When these two are combined, you get insights into how load delays might carry over into sluggish interactivity — or whether responsive issues persist even after a fast load.
Healthy INP by LCP sample
Should you worry
A healthy INP by LCP view shows:
Sessions with fast LCP also have fast INP.
Users can interact almost immediately after content appears.
There’s no lag between “I see it” and “I can use it.”
This means you’re not just rendering fast — you’re delivering usable content quickly too. No frustrating delays, no misleading "ready" states. Just smooth, fast UX.
Unhealthy INP by LCP sample
Problems show up when:
Slow LCP, slow INP: Users wait for the content to load and then wait again for it to respond. This often points to heavy scripts, bloated frameworks, or too much client-side work post-render.
Fast LCP, slow INP: Users see the content fast but can’t use it right away. Maybe hydration is blocking, scripts are still loading, or the main thread is busy.
Slow LCP, fast INP: This is rare, but may signal good interactivity once the page finally loads — yet the delay getting there is still a major problem.
In all cases, mismatches between LCP and INP tell you the experience feels disjointed — fast to see, slow to use, or slow throughout.
Resolving unhealthy INP by LCP
Go-to action plan to resolve an unhealthy INP by LCP:
Ask Uxi to analyze your INP by LCP values and suggest improvements.
Use Filters to focus on high-LCP page types or device types and investigate their INP behavior.
Simulate INP of the suspected lens to see if fixing it will resolve the INP by LCP. If yes, this is where the resolution focus should be.
Use an automated INP optimization tool like INProve to improve your INP by LCP values.
Once you’ve improved INP, set an alert to be the first to know if it starts worsening again.
Try it yourself
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