INP replaces FID as a Core Web Vital
Interaction to Next Paint became an official Core Web Vital on 12 March 2024, and First Input Delay was retired.
What changed
As announced ten months earlier, Google swapped First Input Delay for Interaction to Next Paint in the Core Web Vitals set. INP measures the latency of all page interactions through to the next paint, with 200ms or less rated good and above 500ms rated poor, and is a much harder metric to pass than FID. Search Console, PageSpeed Insights and the Chrome UX Report switched over on the same date, and FID was fully removed from tooling in September 2024.
Timing
Announced on 10 May 2023, with rollout beginning 12 March 2024. 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.