This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The supports() method of the DOMTokenList interface returns true if a given token is in the associated attribute's supported tokens. This method is intended to support feature detection.


var boolean = element.supports(token)


A DOMString containing the token to query for.


A Boolean indicating whether the token was found.


var iframe = document.getElementById('display');
if (iframe.sandbox.supports('an-upcoming-feature')) {
  // support code for mystery future feature
} else {
  // fallback code
if (iframe.sandbox.supports('allow-scripts')) {
  // instruct frame to run JavaScript
   // NOTE: this is well-supported, and just an example!


Specification Status Comment
Credential Management Level 1 Editor's Draft Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 50.0 49 (49) No support ? ?
Feature Android Android Webview Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support 50.0 49.0 (49) No support No support No support 50.0


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