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

Syntax

var altKeyPressed = instanceOfKeyboardEvent.altKey

Examples

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

<script type="text/javascript">

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

</script>
</head>

<body onkeypress="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

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes Yes Yes Yes Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support ? ? Yes ? ? ? ?

See also

Document Tags and Contributors

Contributors to this page: fscholz, libbymc, cvrebert, teoli
Last updated by: fscholz,