What is INP by device pixel ratio
INP by device pixel ratio reveals how Interaction to Next Paint (INP) varies depending on the device’s screen density — reported as the device pixel ratio (DPR). Common values are 1x, 2x, 3x, and fractional values like 1.25x.
DPR reflects how many physical pixels exist per CSS pixel. Higher DPRs usually indicate more powerful screens — like Retina displays — but they can also reveal rendering complexity or hardware strain.
Healthy INP by device pixel ratio sample
Should you worry
If INP is consistently green across all DPR groups — especially 2x and 3x which are common on high-end devices — it means your site is:
Responding quickly to user input
Avoiding unnecessary layout or rendering changes after taps/clicks
Keeping animations and interactivity smooth even on denser screens
That’s the goal: same experience, regardless of pixel density.
Unhealthy INP by device pixel ratio sample
Problems show up when specific DPR groups — often either very high or very low — exhibit interaction delay.
Here’s what might be going wrong:
Heavy visual updates post-interaction (e.g. large high-res image loads or DOM swaps)
Animation jank on lower-end devices with low DPRs (e.g. 1x)
Excessive DOM complexity that hits the main thread harder on small-screen, high-DPR devices
Bad scaling logic, where interaction triggers resizes or style recalculations based on DPR
Think of this breakdown as a signal that your multilingual logic might be affecting interactivity.
Resolving unhealthy INP by device pixel ratio
Go-to action plan to resolve an unhealthy INP by device pixel ratio:
Ask Uxi to analyze your INP by device pixel ratio values and suggest improvements.
Filter with CPU cores, RAM, or screen resolution to spot device class patterns.
Simulate INP of the suspected breakdown to see if fixing it will resolve the INP by device pixel ratio. If yes, this is where the resolution focus should be.
Use an automated INP optimization tool like INProve to improve your INP by device pixel ratio 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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