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

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic support
Chrome Full support 49Edge Full support 17Firefox Full support 49IE No support NoOpera Full support 36Safari ? WebView Android Full support 49Chrome Android Full support 49Edge Mobile No support NoFirefox Android Full support 49Opera Android Full support 36Safari iOS No support NoSamsung Internet Android Full support 5.0


Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

Document Tags and Contributors

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