EventSource: message event

The message event of the EventSource API is fired when data is received through an event source.

Bubbles No
Cancelable No
Interface MessageEvent
Event handler property EventSource.onmessage

Examples

In this basic example, an EventSource is created to receive events from the server; a page with the name sse.php is responsible for generating the events.

var evtSource = new EventSource('sse.php');
var eventList = document.querySelector('ul');

evtSource.addEventListener('message', (e) => {
  var newElement = document.createElement("li");

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

onmessage equivalent

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

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

Specifications

Specification Status
HTML Living Standard
The definition of 'message event' in that specification.
Living Standard

Browser compatibility

BCD tables only load in the browser

See also