EventSource: readyState property

The readyState read-only property of the EventSource interface returns a number representing the state of the connection.

Value

A number which is one of the three possible state constants defined on the EventSource interface:

EventSource.CONNECTING (0)

The connection is not yet open.

EventSource.OPEN (1)

The connection is open and ready to communicate.

EventSource.CLOSED (2)

The connection is closed or couldn't be opened.

Examples

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

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

Specifications

Specification
HTML Standard
# dom-eventsource-readystate-dev

Browser compatibility

BCD tables only load in the browser

See also