FID has left Chrome's performance tooling

Chrome has officially retired First Input Delay (FID) from its performance tools. The metric—which was replaced by Interaction to Next Paint (INP) as a Core Web Vital in May—is no longer supported in Chrome's tooling as of today, September 10, 2024.

What hasn't changed is Chromium's underlying support for first-input entries in the PerformanceObserver API. Developers who still need to measure FID in their applications can continue to do so at the API level.

Tooling changes

The retirement affects where and how FID data is reported across Chrome's suite of performance products:

  • PageSpeed Insights stops showing FID data in its real-user experiences section, and its API stops serving FIRST_INPUT_DELAY_MS data.
  • The CrUX API and CrUX History API will no longer serve data for the first_input_delay metric.
  • The CrUX Dashboard removes its First Input Delay page entirely.
  • The CrUX BigQuery project removes the first_input struct from its schema starting with the 202409 dataset, due to be published in October 2024. Materialized and experimental tables cease reporting new FID data at that point, but historical FID data remains available.
  • The web-vitals.js library drops the onFID function in its next major release, version 5.0. This is a breaking change; release notes will be posted in the repository.
  • The Web Vitals extension no longer reports FID on any surface, including its overlay panel and console logs.

These changes roll out over the next few days.

Documentation updates on web.dev

FID's canonical article on web.dev stays up for posterity but will carry a warning that FID's use is discouraged in favor of INP. The separate Optimize FID article is being removed—its best practices have been superseded by INP—and will permanently redirect to the Optimize INP article.

The shift to INP wraps up a transition that began long before the metric swap earlier this year. INP was designed to capture responsive interaction issues—and, in particular, the delays tied to all input types across a user's session—that FID, by definition, could not see. Removing FID from Chrome's tooling is the final push to get developers fully onto INP for measuring interaction performance.