EventSource: error event

The error event of the EventSource API is fired when a connection with an event source fails to be opened.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("error", (event) => {});

onerror = (event) => {};

Event type

A generic Event.

Examples

js
const evtSource = new EventSource("sse.php");

// addEventListener version
evtSource.addEventListener("error", (e) => {
  console.log("An error occurred while attempting to connect.");
});

// onerror version
evtSource.onerror = (e) => {
  console.log("An error occurred while attempting to connect.");
};

Specifications

Specification
HTML Standard
# event-error
HTML Standard
# handler-eventsource-onerror

Browser compatibility

Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
Deno
error event

See also