Mobile INP performance: The elephant in the room

Earlier this year, when Google announced that Interaction to Next Paint (INP) will replace First Input Delay (FID) as the responsiveness metric in Core Web Vitals in gulp March of 2024, we had a lot to say about it . (TLDR: FID doesn’t correlate with real user behavior, so we don’t endorse it as a meaningful metric.) Our stance hasn’t changed much since then. For the most part, everyone agrees the transition from FID to INP is a good thing.