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

BCD tables only load in the browser

See also