Event timing performance entriesBaseline · Newly available

An event or first-input performance entry measures the latency of user input events, such as mouse clicks or keypresses. They're used to calculate interaction to next paint (INP), a common metric for perceived responsiveness.

Works in the latest version of every major browser, but older devices may not support it yet. Baseline since Dec 12, 2025.

How to use ↓Compare browsers

Browser support

DesktopChrome

1–75Not supported

76+Supportedsince Jul 30, 2019

Current: 155

Edge

12–18Not supported

79+Supportedsince Jan 15, 2020

Current: 154

Firefox

1–88Not supported

89+Supportedsince Jun 1, 2021

Current: 157

Safari

1–26.1Not supported

26.2+Supportedsince Dec 12, 2025

Current: 27

MobileChrome Android

18–75Not supported

76+Supportedsince Jul 30, 2019

Current: 155

Firefox Android

4–88Not supported

89+Supportedsince Jun 1, 2021

Current: 157

Safari iOS

1–26.1Not supported

26.2+Supportedsince Dec 12, 2025

Current: 27

How to use

Every current browser supports this, but it only became Baseline on Dec 12, 2025. Use it as a progressive enhancement, or keep a fallback if you support older devices.

Example

Full syntax and examples are on MDN: EventCounts.

Feature detection

JS · check before using

if ("PerformanceEventTiming" in globalThis) {
  // PerformanceEventTiming is available
} else {
  // load a polyfill or use a fallback
}

Documentation (MDN)

Specification

w3c.github.io/event-timing ↗

Sub-features

Support for each part of the feature (17). The overall table above shows when the whole feature works.

Sub-feature	Chrome	Edge	Firefox	Safari	Chrome Android	Firefox Android	Safari iOS
EventCounts	85	85	89	26.2	85	89	26.2
EventCounts.@@iterator	85	85	89	26.2	85	89	26.2
EventCounts.entries	85	85	89	26.2	85	89	26.2
EventCounts.forEach	85	85	89	26.2	85	89	26.2
EventCounts.get	85	85	89	26.2	85	89	26.2
EventCounts.has	85	85	89	26.2	85	89	26.2
EventCounts.keys	85	85	89	26.2	85	89	26.2
EventCounts.size	85	85	89	26.2	85	89	26.2
EventCounts.values	85	85	89	26.2	85	89	26.2
Performance.eventCounts	85	85	89	26.2	85	89	26.2
PerformanceEventTiming	76	79	89	26.2	76	89	26.2
PerformanceEventTiming.cancelable	76	79	89	26.2	76	89	26.2
PerformanceEventTiming.interactionId	96	96	144	26.2	96	144	26.2
PerformanceEventTiming.processingEnd	76	79	89	26.2	76	89	26.2
PerformanceEventTiming.processingStart	76	79	89	26.2	76	89	26.2
PerformanceEventTiming.target	85	85	89	26.2	85	89	26.2
PerformanceEventTiming.toJSON	76	79	89	26.2	76	89	26.2