EventsBaseline · Widely available
The Event API and the addEventListener() method on objects that receive events (event targets) represent and handle significant things happening on a page. Many APIs fire events for a wide range of situations relating to those APIs, such as an image loading, a user clicking, or a value changing.
Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since Jul 29, 2015. Widely available since Jan 29, 2018.
Browser support
DesktopChrome
1+Supportedsince Dec 11, 2008
Current: 155Edge
12+Supportedsince Jul 29, 2015
Current: 154Firefox
1+Supportedsince Nov 9, 2004
Current: 157Safari
1+Supportedsince Jun 23, 2003
Current: 27MobileChrome Android
18+Supportedsince Jun 27, 2012
Current: 155Firefox Android
4+Supportedsince Mar 29, 2011
Current: 157Safari iOS
1+Supportedsince Jun 29, 2007
Current: 27How to use
This feature is Baseline widely available — use it freely, no fallback needed.
Example
Full syntax and examples are on MDN: CustomEvent.
Feature detection
JS · check before using
if ("Event" in globalThis) {
// Event is available
} else {
// load a polyfill or use a fallback
}Sub-features
Support for each part of the feature (33). The overall table above shows when the whole feature works.
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| CustomEvent | 5 | 12 | 6 | 5 | 18 | 6 | 5 |
| CustomEvent.CustomEvent | 15 | 12 | 11 | 6 | 18 | 14 | 6 |
| CustomEvent.detail | 5 | 12 | 6 | 5 | 18 | 6 | 5 |
| CustomEvent.worker_support | 43 | 17 | 48 | 12 | 43 | 48 | 12 |
| Event | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| Event.Event | 15 | 12 | 11 | 6 | 18 | 14 | 6 |
| Event.bubbles | 1 | 12 | 1.5 | 1 | 18 | 4 | 1 |
| Event.cancelable | 1 | 12 | 1.5 | 1 | 18 | 4 | 1 |
| Event.currentTarget | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| Event.defaultPrevented | 5 | 12 | 6 | 5 | 18 | 6 | 5 |
| Event.eventPhase | 1 | 12 | 1.5 | 1 | 18 | 4 | 1 |
| Event.isTrusted | 46 | 12 | 1.5 | 10 | 46 | 4 | 10 |
| Event.preventDefault | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| Event.stopImmediatePropagation | 5 | 12 | 10 | 5 | 18 | 10 | 5 |
| Event.stopPropagation | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| Event.target | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| Event.timeStamp | 1 | 12 | 1.5 | 1 | 18 | 4 | 1 |
| Event.type | 1 | 12 | 1.5 | 1 | 18 | 4 | 1 |
| EventTarget | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| EventTarget.EventTarget | 64 | 79 | 59 | 14 | 64 | 59 | 14 |
Show 13 more
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| EventTarget.addEventListener | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| EventTarget.addEventListener.options_parameter | 49 | 16 | 49 | 10 | 49 | 49 | 10 |
| EventTarget.addEventListener.options_parameter.options_capture_parameter | 49 | 16 | 49 | 10 | 49 | 49 | 10 |
| EventTarget.addEventListener.options_parameter.options_once_parameter | 55 | 16 | 50 | 10 | 55 | 50 | 10 |
| EventTarget.addEventListener.options_parameter.options_passive_parameter | 51 | 16 | 49 | 10 | 51 | 49 | 10 |
| EventTarget.addEventListener.options_parameter.options_passive_parameter_default_true_touch | 55 | 79 | 61 | 11.1 | 55 | 61 | 11.3 |
| EventTarget.addEventListener.options_parameter.options_passive_parameter_default_true_wheel | 73 | 79 | 84 | ✕ | 73 | 84 | ✕ |
| EventTarget.addEventListener.options_parameter.options_signal_parameter | 90 | 90 | 86 | 15 | 90 | 86 | 15 |
| EventTarget.addEventListener.useCapture_parameter_optional | 1 | 12 | 6 | 1 | 18 | 6 | 1 |
| EventTarget.dispatchEvent | 4 | 12 | 2 | 3.1 | 18 | 4 | 3 |
| EventTarget.removeEventListener | 1 | 12 | 1 | 1 | 18 | 4 | 1 |
| EventTarget.removeEventListener.options_parameter | 49 | 16 | 49 | 10 | 49 | 49 | 10 |
| EventTarget.removeEventListener.useCapture_parameter_optional | 1 | 12 | 6 | 1 | 18 | 6 | 1 |