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LCP by INP

LCP by INP

Vasil Dachev avatar
Written by Vasil Dachev
Updated this week

What is LCP by INP

LCP by INP bridges two of the most important user-facing web metrics Largest Contentful Paint (LCP) and Interaction to Next Paint (INP).

This lens shows how fast your page loads depending on how responsive it later becomes. You’ll see whether slow LCPs correlate with poor INP, or whether interaction issues happen even when LCP is fast.

It helps answer: “Do pages that load slowly also interact poorly?

Healthy LCP by INP sample


Should you worry

In a healthy experience, good INP correlates with green LCP. These are the magic combinations:

  • Fast load + fast interaction = happy users.

  • Pages feel smooth and fluid.

  • Users can act as soon as they see the content.

If your LCP is fast and your INP is in the green, that’s a very strong signal that your critical rendering and JavaScript execution are well-optimized.

Unhealthy LCP by INP sample

Problems start showing when:

  • Good INP, slow LCP: The page responds well once it’s visible — but the user has to wait too long to even get there.

  • Slow INP, fast LCP: The content appears fast, but the page feels janky, unclickable, or delayed when users try to interact. This is often caused by JavaScript blocking, excessive tasks, or third-party scripts hijacking the main thread.

In both cases, there's a disjointed experience: either too slow to show up, or too slow to do anything after showing up.


Resolving unhealthy LCP by INP

Go-to action plan to resolve an unhealthy LCP by INP:

  1. Ask Uxi to analyze your LCP by INP values and suggest improvements.

  2. Use Filters to isolate the bad INP group and compare their LCP values with other lenses like layout, device type, or third-party presence.

  3. Simulate LCP of the suspected lens to see if fixing it will resolve the slow LCP by INP. If yes, this is where the resolution focus should be.

  4. Use an automated LCP optimization tool like Navigation AI to improve your LCP by INP values.

  5. Once you’ve improved LCP, set an alert to be the first to know if it starts worsening again.

Try it yourself

Discover how your website performs with real user data.

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