HTMLScriptElement: supports() static method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2022.

See full compatibility

The supports() static method of the HTMLScriptElement interface provides a simple and consistent method to feature-detect what types of scripts are supported by the user agent.

The method is expected to return true for classic and module scripts, which are supported by most modern browsers.

Syntax

HTMLScriptElement.supports(type)

Parameters

type

A string literal that indicates the type of script for which support is to be checked. Supported values are case sensitive, and include:

"classic": Test if classic scripts are supported. "Classic" scripts are the normal/traditional JavaScript files that predate module scripts.
"module": Test if module scripts are supported.
"importmap": Test if import maps are supported.
"speculationrules": Test if speculation rules are supported and enabled.

Any other value will cause the method to return false.

Return value

Returns true if the indicated script type is supported and false otherwise.

Examples

The code below shows how to check if HTMLScriptElement.supports() is defined, and if so, to use it to test whether particular types of scripts are supported.

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

function checkSupport(type) {
  const result = HTMLScriptElement.supports(type) ? "true" : "false";
  log.textContent += `HTMLScriptElement.supports('${type}') is ${result}\n`;
}

if (typeof HTMLScriptElement.supports === "undefined") {
  log.textContent = "HTMLScriptElement.supports() method is not supported";
} else {
  // Check if various script types are supported
  checkSupport("module");
  checkSupport("classic");
  checkSupport("importmap");
  checkSupport("speculationrules");
  // Any other value will cause the method to return false
  checkSupport("anything else");
}

<textarea id="log" rows="6" cols="80"></textarea>

Specifications

Specification
HTML # dom-script-supports-dev

Browser compatibility

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`supports()` static method	Chrome – Full support Chrome 96 (Release date: 2021-11-15) footnote Full support	Edge – Full support Edge 96 (Release date: 2021-11-19) footnote Full support	Firefox – Full support Firefox 94 (Release date: 2021-11-02) footnote Full support	Opera – Full support Opera 82 (Release date: 2021-12-02) footnote Full support	Safari – Full support Safari 16 (Release date: 2022-09-12) footnote Full support	Chrome Android – Full support Chrome Android 96 (Release date: 2021-11-15) footnote Full support	Firefox for Android – Full support Firefox for Android 94 (Release date: 2021-11-02) footnote Full support	Opera Android – Full support Opera Android 67 (Release date: 2022-01-31) footnote Full support	Safari on iOS – Full support Safari on iOS 16 (Release date: 2022-09-12) footnote Full support	Samsung Internet – Full support Samsung Internet 17 (Release date: 2022-05-04) footnote Full support	WebView Android – Full support WebView Android 96 (Release date: 2021-11-15) footnote Full support	WebView on iOS – Full support WebView on iOS 16 (Release date: 2022-09-12) footnote Full support

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Full support: Full support