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HTMLScriptElement: supports() static method

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

js

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.

js

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");
}

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
supports_static 96 96 94 No 82 16 96 96 94 67 16 17.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/HTMLScriptElement/supports_static