Updated January 18, 2024.
Interaction to Next Paint (INP) measures your site’s responsiveness to user interactions on the page. The faster your page responds to user input, the better.
On March 12, 2024, INP will officially replace First Input Delay (FID) as the third Core Web Vital.
This post will help you understand why INP is a better way to measure responsiveness than FID and how React and Next.js can improve INP. You'll be prepared for updates to Core Web Vitals, which impact search rankings, as INP moves from experimental to stable. We have a separate post on understanding the metric and further optimization of INP.