KeyboardEvent.altKey

The KeyboardEvent.altKey read-only property is a Boolean 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

Boolean

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

Specification Status Comment
Document Object Model (DOM) Level 3 Events Specification
The definition of 'KeyboardEvent.altkey' in that specification.
Obsolete Initial definition.

Browser compatibility

BCD tables only load in the browser

See also