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This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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 Working Draft Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support50 ?49 No Yes ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support5050 ?49 Yes No ?

Document Tags and Contributors

 Contributors to this page: fscholz, chrisdavidmills, teoli, jpmedley
 Last updated by: fscholz,