Interaction to Next Paint (INP)
01 Definition
Interaction to Next Paint (INP) meaning: INP measures how quickly a page responds to user interactions across a visit.
Interaction to Next Paint is a Core Web Vitals metric from Google that measures responsiveness by tracking the delay between user interactions and the next screen update. It replaced First Input Delay in 2024. Google considers 200 milliseconds or less at the 75th percentile a good score.
Also called
Why it matters
How Interaction to Next Paint (INP) fits the work
INP is Google's responsiveness signal within Core Web Vitals, so a low score reflects a page that reacts quickly when people click and tap.
In context
After splitting a large script and deferring nonessential code, the site's INP improved from 340 milliseconds to 180 milliseconds at the 75th percentile.
Practical note
Heavy JavaScript on the main thread is a common cause of poor INP. Unlike the older First Input Delay, INP considers all interactions during a visit, not just the first.