INP announced as replacement for FID
Google announced that Interaction to Next Paint would replace First Input Delay as the Core Web Vitals responsiveness metric in March 2024.
What changed
Google gave ten months' notice that Interaction to Next Paint would become a Core Web Vital, replacing First Input Delay, because FID measured only input delay on the first interaction and most pages passed it trivially. INP measures the full latency of all interactions through to the next visual update, with a good threshold of 200 milliseconds. Google added INP to Search Console, PageSpeed Insights and the Chrome UX Report during the transition period.
Timing
Rollout began 10 May 2023. No completion date was announced. Rankings typically remain unstable for the whole rollout window, so measurements taken inside it are not a reliable read on the outcome.