EventSource: error event

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

Bubbles No
Cancelable No
Interface Event or ErrorEvent
Event handler property EventSource.onerror


var 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.");


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

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
error eventChrome Full support 6Edge Full support 79Firefox Full support 6IE No support NoOpera Full support YesSafari Full support 5WebView Android Full support YesChrome Android Full support 18Firefox Android Full support 45Opera Android Full support 12Safari iOS Full support 5Samsung Internet Android Full support 1.0


Full support
Full support
No support
No support

See also