First Input Timing
The PerformanceEventTiming interface provides timing information about the latency of the first discrete user interaction, specifically one of key down, mouse down, click, a pointer down followed by a pointer up. (Pointer down may be the start of scrolling, which is not tracked.) This is a subset of the EventTiming API, but will be exposed in advance because it provides key metrics to help measure and optimize responsiveness.
Status in Chromium
Enabled by default (tracking bug) in:
- Chrome for desktop release 77
- Chrome for Android release 77
Consensus & Standardization
Last updated on 2019-08-01