HTMLScriptElement: async 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 async property of the HTMLScriptElement interface is a boolean value that controls how the script should be executed. For classic scripts, if the async property is set to true, the external script will be fetched in parallel to parsing and evaluated as soon as it is available. For module scripts, if the async property is set to true, the script and all their dependencies will be fetched in parallel to parsing and evaluated as soon as they are available.

It reflects the async attribute of the <script> element.

Value

A boolean.

Examples

html
<script id="el" src="/example.js" async></script>
js
const el = document.getElementById("el");
console.log(el.async); // Output: true

Specifications

Specification
HTML
# dom-script-async

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
async

Legend

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Full support
Full support

See also