FID Is Dead. What INP Means for Your React App.

In March 2024, Google replaced First Input Delay with Interaction to Next Paint as an official Core Web Vital. FID is gone. INP is what matters now — and most React apps that were passing before are failing under the new standard without anyone realizing it. What was wrong with FID FID measured how long the browser took to respond to the very first user interaction on a page. Click a button, FID measures the delay before the browser started processing that click. Just the first one. Just the sta