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 PushMessageData interface of the Push API provides methods which let you retrieve the push data sent by a server in various formats.

Unlike the similar methods in the Fetch API, which only allow the method to be invoked once, these methods can be called multiple times.




Extracts the data as an ArrayBuffer object.
Extracts the data as a Blob object.
Extracts the data as a JSON object.
Extracts the data as a plain text string.


In our Push API Demo, we send JSON objects via push messages from our server by first converting them to strings via JSON.stringify() (see server.js example):

webPush.sendNotification(subscriber[2], 200, obj.key, JSON.stringify({
  action: 'chatMsg',
  name: obj.name,
  msg: obj.msg

When the message reaches the service worker, we convert the data back to a JSON object using PushMessageData.json() before working out what to do with it next:

self.addEventListener('push', function(event) {
  var obj = event.data.json();
  if(obj.action === 'subscribe' || obj.action === 'unsubscribe') {
    fireNotification(obj, event);
  } else if(obj.action === 'init' || obj.action === 'chatMsg') {


Specification Status Comment
Push API
The definition of 'PushMessageData' in that specification.
Working Draft Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 50.0 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 50.0

See also