INP (Interaction to Next Paint)
Definition
Interaction to Next Paint measures how quickly a page visually responds after user interactions such as taps, clicks, and key presses.
By Vinespire Editorial Team, Editorial ·
This term is part of the full AI search glossary.
Full definition
INP observes latency from interaction to the next paint across the page lifecycle and summarizes how responsive the experience feels. Long tasks on the main thread—heavy JavaScript, large DOM updates— inflate INP.
It replaced First Input Delay (FID) as the Core Web Vital for interactivity. Optimization focuses on breaking up long tasks, deferring non-essential script work, and keeping event handlers lean.
INP is a UX metric, not an AI-specific score, but sluggish pages still frustrate humans who verify citations from answer engines. See Core Web Vitals and Hydration.