Web/API/EventSource/onmessage

The onmessage property of the EventSource interface is an EventHandler called when a message event is received, that is when a message is coming from the source.

Event objects of onmessage event handers are of type MessageEvent.

Syntax

eventSource.onmessage = function

Examples

evtSource.onmessage = function(e) {
  var newElement = document.createElement("li");

  newElement.textContent = "message: " + e.data;
  eventList.appendChild(newElement);
}

Note: You can find a full example on GitHub — see Simple SSE demo using PHP.

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of 'onmessage' in that specification.	Living Standard	Initial definition

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`onmessage`	Chrome Full support 6	Edge Full support 79	Firefox Full support 6	IE No support No	Opera Full support Yes	Safari Full support 5	WebView Android Full support Yes	Chrome Android Full support 18	Firefox Android Full support 45	Opera Android Full support 12	Safari iOS Full support 5	Samsung Internet Android Full support 1.0

Legend

Full support: Full support
No support: No support