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EventSource: close() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨January 2020⁩.

Note: This feature is available in Web Workers.

The close() method of the EventSource interface closes the connection, if one is made, and sets the EventSource.readyState attribute to 2 (closed).

Note: If the connection is already closed, the method does nothing.

Syntax

close()

Parameters

None.

Return value

None (undefined).

Examples

const button = document.querySelector("button");
const evtSource = new EventSource("sse.php");

button.onclick = () => {
  console.log("Connection closed");
  evtSource.close();
};

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

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android WebView on iOS
close 6 79 6 12 5 18 45 12 5 1.0 4.4 5

See also

© 2005–2025 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/EventSource/close