INP (Interaction to Next Paint) is a Core Web Vitals metric introduced by Google to measure web responsiveness.

  • It tracks the latency of all user interactions (like clicks, taps, or key presses) on a page.
  • INP reports the longest interaction delay before the next frame is painted.
  • A good INP score is 200 ms or less, meaning the site feels fast and responsive.

It replaces FID (First Input Delay) as the main responsiveness metric starting March 2024.