Interaction to Next Paint (INP)
TL;DR
INP measures how quickly a page visually responds to user interactions like clicks, taps and keyboard input — the successor to FID since 2024.
Interaction to Next Paint replaced First Input Delay in Google's Core Web Vitals in March 2024. Where FID only measured the first interaction, INP looks at all interactions during a visit and takes the worst 98th percentile. Below 200ms is good, above 500ms poor.
Example
An e-commerce site scores INP 620ms on product pages. Cause: a heavy JS bundle that re-renders on every click. After code-splitting and deferred hydration INP drops to 180ms.
Frequently asked questions
How do I improve INP?
Break long tasks (>50ms), make event handlers lighter, defer long tasks with scheduler.yield or requestIdleCallback, and defer third-party scripts.
Related terms
Further reading
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