MDN’s new design is in Beta! A sneak peek:

This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Avoid using it and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The KeyboardEvent.which read-only property returns the numeric keyCode of the key pressed, or the character code (charCode) for an alphanumeric key pressed.


var keyResult = event.which;
  • keyResult contains the numeric code for a particular key pressed, depending on whether an alphanumeric or non-alphanumeric key was pressed. Please see KeyboardEvent.charCode and KeyboardEvent.keyCode for more details.


<title>charCode/keyCode/which example</title>

<script type="text/javascript">

function showKeyPress(evt)
alert("onkeypress handler: \n"
      + "keyCode property: " + evt.keyCode + "\n"
      + "which property: " + evt.which + "\n"
      + "charCode property: " + evt.charCode + "\n"
      + "Character Key Pressed: "
      + String.fromCharCode(evt.charCode) + "\n"

function keyDown(evt)
alert("onkeydown handler: \n"
      + "keyCode property: " + evt.keyCode + "\n"
      + "which property: " + evt.which + "\n"



<p>Please press any key.</p>



Specification Status Comment
Document Object Model (DOM) Level 3 Events Specification
The definition of 'KeyboardEvent.which' in that specification.
Working Draft Initial definition; specified as deprecated

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support 4 (Yes) 2 [1] 9 10.10 5.1
Feature Android Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes)[1] 10 ? 5.1

[1] Gecko implements this property on the UIEvent interface.

See also

Document Tags and Contributors

 Last updated by: julienw,