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 |