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 getKey() method of the PushSubscription interface returns an ArrayBuffer representing a client public key, which can then be sent to a server and used in encrypting push message data.

Note: This is currently Firefox-only, and not yet included in the Push API spec


​var key = subscription.getKey(method);


The encryption method used to generate the client public key. p256dh is currently the only option. The method value can be:
  • p256dh: an Elliptic curve Diffie–Hellman public key on the P-256 curve (that is, the NIST secp256r1 elliptic curve).  The resulting key is an uncompressed point in ANSI X9.62 format.


An ArrayBuffer.


In our Push API demo, we call getKey('p256dh') and PushSubscription.endpoint to get the necessary credentials we need to  encrypt push message data, and send push messages from our server to specific subscribers.

  .then(function(subscription) {  
  // Enable any UI which subscribes / unsubscribes from  
  // push messages.  
  subBtn.disabled = false;

  if (!subscription) {  
    console.log('Not yet subscribed to Push')
    // We aren't subscribed to push, so set UI  
    // to allow the user to enable push  

  // Set your UI to show they have subscribed for  
  // push messages  
  subBtn.textContent = 'Unsubscribe from Push Messaging';  
  isPushEnabled = true;  
  // initialize status, which includes setting UI elements for subscribed status
  // and updating Subscribers list via push
  var endpoint = subscription.endpoint;
  var key = subscription.getKey('p256dh');



Specification Status Comment
Push API Working Draft This is the Push API spec, but note that getKey() is not currently specified in here. It is currently Firefox-only experimental.

Browser Compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support No support 44.0 (44.0)[1] No support No support No support
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support No support 48.0 (48)[2] No support No support No support No support No support

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Experimental getKey Method Non-standard Push Push API PushSubscription Reference Service Workers