KeyboardEvent.altKey

The KeyboardEvent.altKey read-only property is a boolean value that indicates if the alt key (Option or on OS X) was pressed (true) or not (false) when the event occurred.

Syntax

var altKeyPressed = instanceOfKeyboardEvent.altKey

Return value

A boolean value

Examples

<html>
<head>
<title>altKey example</title>

<script type="text/javascript">

function showChar(e){
  alert(
    "Key KeyDown: " + String.fromCharCode(e.charCode) + "\n"
    + "charCode: " + e.charCode + "\n"
    + "ALT key KeyDown: " + e.altKey + "\n"
  );
}

</script>
</head>

<body onkeydown="showChar(event);">
<p>
Press any character key,
with or without holding down the ALT key.<br />
You can also use the SHIFT key together with the ALT key.
</p>
</body>
</html>

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
altKey
1
12
1.5
9
≤12.1
≤4
≤37
18
4
≤12.1
≤3
1.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/altKey