The EventTarget.removeEventListener()
method removes from the EventTarget
an event listener previously registered with EventTarget.addEventListener()
. The event listener to be removed is identified using a combination of the event type, the event listener function itself, and various optional options that may affect the matching process; see Matching event listeners for removal
Syntax
target.removeEventListener(type, listener[, options]);
target.removeEventListener(type, listener[, useCapture]);
Parameters
type
- A string which specifies the type of event for which to remove an event.
listener
- The
EventListener
function of the event handler to remove from the event target. options
Optional- An options object that specifies characteristics about the event listener. The available options are:
capture
: ABoolean
that indicates that events of this type will be dispatched to the registeredlistener
before being dispatched to anyEventTarget
beneath it in the DOM tree.passive
: ABoolean
indicating that thelistener
will never callpreventDefault()
. If it does, the user agent should ignore it and generate a console warning.-
mozSystemGroup
: Available only in code running in XBL or in Firefox' chrome, it is aBoolean
defining if the listener is added to the system group.
useCapture
Optional- Specifies whether the
EventListener
to be removed is registered as a capturing listener or not. If this parameter is absent, a default value offalse
is assumed. - If a listener is registered twice, one with capture and one without, remove each one separately. Removal of a capturing listener does not affect a non-capturing version of the same listener, and vice versa.
Return value
undefined
.
Matching event listeners for removal
Given an event listener previously added by calling addEventListener()
, you may eventually come to a point at which you need to remove it. Obviously, you need to specify the same type
and listener
parameters to removeEventListener()
, but what about the options
or useCapture
parameters?
While addEventListener()
will let you add the same listener more than once for the same type if the options are different, the only option removeEventListener()
checks is the capture
/useCapture
flag. Its value must match for removeEventListener()
to match, but the other values don't.
For example, consider this call to addEventListener()
:
element.addEventListener("mousedown", handleMouseDown, true);
Now consider each of these two calls to removeEventListener()
:
element.removeEventListener("mousedown", handleMouseDown, false); // Fails element.removeEventListener("mousedown", handleMouseDown, true); // Succeeds
The first call fails because the value of useCapture
doesn't match. The second succeeds, since useCapture
matches up.
Now consider this:
element.addEventListener("mousedown", handleMouseDown, { passive: true });
Here, we specify an options
object in which passive
is set to true
, while the other options are left to the default value of false
.
Now look at each of these calls to removeEventListener()
in turn. Any of them in which capture
or useCapture
is true
fail; all others succeed. Only the capture
setting matters to removeEventListener()
.
element.removeEventListener("mousedown", handleMouseDown, { passive: true }); // Succeeds element.removeEventListener("mousedown", handleMouseDown, { capture: false }); // Succeeds element.removeEventListener("mousedown", handleMouseDown, { capture: true }); // Fails element.removeEventListener("mousedown", handleMouseDown, { passive: false }); // Succeeds element.removeEventListener("mousedown", handleMouseDown, false); // Succeeds element.removeEventListener("mousedown", handleMouseDown, true); // Fails
It's worth noting that some browser releases have been inconsistent on this, and unless you have specific reasons otherwise, it's probably wise to use the same values used for the call to addEventListener()
when calling removeEventListener()
.
Notes
If an EventListener
is removed from an EventTarget
while it is processing an event, it will not be triggered by the current actions. An EventListener
will not be invoked for the event it was registered for after being removed. However, it can be reattached.
Calling removeEventListener()
with arguments that do not identify any currently registered EventListener
on the EventTarget
has no effect.
Example
This example shows how to add a click
-based event listener and remove a mouseover
-based event listener.
var body = document.querySelector('body'), clickTarget = document.getElementById('click-target'), mouseOverTarget = document.getElementById('mouse-over-target'), toggle = false; function makeBackgroundYellow() { 'use strict'; if (toggle) { body.style.backgroundColor = 'white'; } else { body.style.backgroundColor = 'yellow'; } toggle = !toggle; } clickTarget.addEventListener('click', makeBackgroundYellow, false ); mouseOverTarget.addEventListener('mouseover', function () { 'use strict'; clickTarget.removeEventListener('click', makeBackgroundYellow, false ); });
Specifications
Specification | Status | Comment |
---|---|---|
DOM The definition of 'EventTarget.removeEventListener()' in that specification. |
Living Standard | |
DOM4 The definition of 'EventTarget.removeEventListener()' in that specification. |
Recommendation | |
Document Object Model (DOM) Level 2 Events Specification The definition of 'EventTarget.removeEventListener()' in that specification. |
Recommendation | Initial definition |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 1.0[1][2] | (Yes) | 1.0 (1.7 or earlier)[3] | 9.0 | 7[4] | 1.0[1] |
useCapture made optional |
(Yes) | (Yes) | 6.0 | 9.0 | 11.60 | (Yes) |
options parameter |
49.0 | No support |
Feature | Android | Android Webview | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|---|
Basic support | 1.0[1] | (Yes)[2] | (Yes) | 1.0 (1)[3] | 9.0 | 6.0[4] | 1.0[1] | (Yes)[2] |
useCapture made optional |
? | (Yes) | (Yes) | (Yes) | ||||
options parameter |
No support | 49.0 | No support | 49.0 |
[1] Although WebKit explicitly added "[optional]
" to the useCapture
parameter for Safari 5.1 and Chrome 13, it had been working before the change.
[2] Before Chrome 49, the type and listener parameters were optional.
[2] Before Firefox 6, the browser would throw an exception if the useCapture
parameter was not explicitly false
. Before Gecko 9.0 (Firefox 9.0 / Thunderbird 9.0 / SeaMonkey 2.6), addEventListener()
would throw an exception if the listener parameter was null
; now the method returns without error, but without doing anything.
[4] Opera 11.60 made the useCapture
parameter optional (source).
[5] For backward compatibility, browsers that support options
allow the third parameter to be either options
or Boolean
.
Polyfill to support older browsers
addEventListener()
and removeEventListener()
are not present in older browsers. You can work around this by inserting the following code at the beginning of your scripts, allowing the use of addEventListener()
and removeEventListener()
in implementations that do not natively support it. However, this method will not work on Internet Explorer 7 or earlier, since extending the Element.prototype was not supported until Internet Explorer 8.
if (!Element.prototype.addEventListener) { var oListeners = {}; function runListeners(oEvent) { if (!oEvent) { oEvent = window.event; } for (var iLstId = 0, iElId = 0, oEvtListeners = oListeners[oEvent.type]; iElId < oEvtListeners.aEls.length; iElId++) { if (oEvtListeners.aEls[iElId] === this) { for (iLstId; iLstId < oEvtListeners.aEvts[iElId].length; iLstId++) { oEvtListeners.aEvts[iElId][iLstId].call(this, oEvent); } break; } } } Element.prototype.addEventListener = function (sEventType, fListener /*, useCapture (will be ignored!) */) { if (oListeners.hasOwnProperty(sEventType)) { var oEvtListeners = oListeners[sEventType]; for (var nElIdx = -1, iElId = 0; iElId < oEvtListeners.aEls.length; iElId++) { if (oEvtListeners.aEls[iElId] === this) { nElIdx = iElId; break; } } if (nElIdx === -1) { oEvtListeners.aEls.push(this); oEvtListeners.aEvts.push([fListener]); this["on" + sEventType] = runListeners; } else { var aElListeners = oEvtListeners.aEvts[nElIdx]; if (this["on" + sEventType] !== runListeners) { aElListeners.splice(0); this["on" + sEventType] = runListeners; } for (var iLstId = 0; iLstId < aElListeners.length; iLstId++) { if (aElListeners[iLstId] === fListener) { return; } } aElListeners.push(fListener); } } else { oListeners[sEventType] = { aEls: [this], aEvts: [ [fListener] ] }; this["on" + sEventType] = runListeners; } }; Element.prototype.removeEventListener = function (sEventType, fListener /*, useCapture (will be ignored!) */) { if (!oListeners.hasOwnProperty(sEventType)) { return; } var oEvtListeners = oListeners[sEventType]; for (var nElIdx = -1, iElId = 0; iElId < oEvtListeners.aEls.length; iElId++) { if (oEvtListeners.aEls[iElId] === this) { nElIdx = iElId; break; } } if (nElIdx === -1) { return; } for (var iLstId = 0, aElListeners = oEvtListeners.aEvts[nElIdx]; iLstId < aElListeners.length; iLstId++) { if (aElListeners[iLstId] === fListener) { aElListeners.splice(iLstId, 1); } } }; }