KeyboardEvent: altKey property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

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

Value

A boolean value.

Examples

html
<!doctype html>
<html lang="en-US">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width" />
    <title>altKey example</title>

    <script>
      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
UI Events
# dom-keyboardevent-altkey

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
altKey

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also