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web api instance property

KeyboardEvent: altKey property

View on MDN ↗

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

<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>
<pre id="output"></pre>

const output = document.getElementById("output");

function showChar(e) {
  output.textContent = `Key KeyDown: "${e.key}"
ALT key KeyDown: ${e.altKey}
`;
}

document.addEventListener("keydown", showChar);
Interactive exampleOpen the canonical MDN source to run this embedded demo.

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also