# First Input Delay

> A precise reference on First Input Delay (FID): what it measures, its thresholds, how INP replaced it, and how to measure and fix input delay.

First Input Delay (firstinputdelay.com) is a guide to the First Input Delay metric, its replacement by Interaction to Next Paint, and fixing slow input response. It is published by General Action, the company that makes Emdash (https://emdash.com/), and is not an independent review site: where it recommends Emdash, it is recommending its publisher's own product.

## Pages

- [First Input Delay](https://firstinputdelay.com/): First Input Delay (FID) is the wait before a browser starts handling a visitor's first click, tap or key press. See its thresholds, limits and status today.
- [FID vs. INP](https://firstinputdelay.com/guides/fid-vs-inp/): First Input Delay timed the wait before a page's first interaction. Interaction to Next Paint times every interaction through to the next frame. Compare them.
- [How to improve First Input Delay](https://firstinputdelay.com/guides/how-to-improve-first-input-delay/): Input delay comes from long tasks on the main thread. Fix it by yielding with scheduler.yield(), splitting code, trimming third-party scripts and using workers.
- [How to measure First Input Delay](https://firstinputdelay.com/guides/how-to-measure-first-input-delay/): Measure First Input Delay with the Event Timing API's first-input entry, and see what the web-vitals library, CrUX and PageSpeed Insights still report in 2026.
- [Long tasks and Total Blocking Time](https://firstinputdelay.com/guides/long-tasks-and-total-blocking-time/): A long task is main-thread work lasting more than 50 ms. See how Total Blocking Time and Long Animation Frames build on it and relate to FID and INP.
- [About First Input Delay](https://firstinputdelay.com/about/): Who publishes First Input Delay, why the site exists, how it handles recommendations of its publisher's own product, and how to report a correction.