Interaction to Next Paint (INP)

Interaction to Next Paint (INP) is the Core Web Vital that measures how quickly your page responds to visitor interactions. Since March 2024, INP has replaced the old metric First Input Delay (FID) as the official Core Web Vital for responsiveness.

What exactly does INP measure?

INP measures the time between an interaction, such as a click or a keystroke, and the moment the browser visibly paints the result. Unlike FID, which only measured the delay of the very first interaction, INP looks at all interactions during the visit and reports the slowest one that is representative. This gives INP a much fairer picture of how fast your site actually feels. Google considers an INP under 200 milliseconds good, between 200 and 500 moderate, and above that poor.

How do you improve your INP?

The biggest culprit is heavy JavaScript that keeps the main thread occupied, preventing the browser from responding to the visitor. Break up long tasks, defer non-essential scripts and reduce third-party code such as trackers and widgets. A CDN and thoughtful lazy-loading help too, because less work up front means a faster response. INP, together with LCP for loading speed and CLS for visual stability, forms the trio of Core Web Vitals.

Why this matters for your growth

At Customer Impact a fast site is about visitors who click through instead of dropping off. In B2B, a decision-maker often goes through several steps before requesting a quote, and every slow response along the way increases the chance they drop off. Good page speed and responsiveness are therefore not a technical luxury, but direct building blocks of your conversion.