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
<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>
js
const output = document.getElementById("output");
function showChar(e) {
output.textContent = `Key KeyDown: "${e.key}"
ALT key KeyDown: ${e.altKey}
`;
}
document.addEventListener("keydown", showChar);
Specifications
| Specification |
|---|
| UI Events # dom-keyboardevent-altkey |