The WebSocket API is an advanced technology that makes it possible to open a two-way interactive communication session between the user's browser and a server. With this API, you can send messages to a server and receive event-driven responses without having to poll the server for a reply.
Note: While a WebSocket connection is functionally somewhat similar to standard Unix-style sockets, they are not related.
WebSocket
CloseEvent
MessageEvent
Specification | Status | Comments |
---|---|---|
HTML Living StandardThe definition of 'WebSocket API' in that specification. | Living Standard | |
WebSockets | Candidate Recommendation | |
RFC 6455: The WebSocket Protocol | IETF RFC |
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | Android webview | Chrome for Android | Firefox for Android | Opera for Android | Safari on iOS | Samsung Internet | |
WebSocket
|
Chrome
Full support 4 |
Edge
Full support 12 |
Firefox Full support 11
Full support 11
No support 7 — 11 Prefixed' Notes' Prefixed' Implemented with the vendor prefix: Moz Notes' Message size limited to 16 MB (see bug 711205). No support 4 — 6 Notes' Notes' Message size limited to 16 MB (see bug 711205). |
IE
Full support 10 |
Opera
Full support 12.1 |
Safari
Full support 5 |
WebView Android
Full support ≤37 |
Chrome Android
Full support 18 |
Firefox Android Full support 14 Notes' Full support 14 Notes' Notes' See bug 695635. No support 7 — 14 Prefixed' Notes' Prefixed' Implemented with the vendor prefix: Moz Notes' Message size limited to 16 MB (see bug 711205). No support 4 — 6 Notes' Notes' Message size limited to 16 MB (see bug 711205). |
Opera Android
Full support 12.1 |
Safari iOS
Full support 4.2 |
Samsung Internet Android
Full support 1.0 |
WebSocket() constructor
|
Chrome
Full support Yes |
Edge
Full support ≤79 |
Firefox Full support 7
Full support 7
No support 4 — 7 Notes' Notes' Parameter |
IE
? |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support 7 |
Opera Android
? |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
binaryType
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
bufferedAmount
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
close
|
Chrome
Full support 4 |
Edge
Full support 12 |
Firefox Full support 8
|
IE
Full support 10 |
Opera
Full support 12.1 |
Safari
Full support 5 |
WebView Android
Full support ≤37 |
Chrome Android
Full support 18 |
Firefox Android Full support 8
|
Opera Android
Full support 12.1 |
Safari iOS
Full support 4.2 |
Samsung Internet Android
Full support 1.0 |
close event
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
? |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
error event
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
? |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
extensions
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support 8 |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support 8 |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
message event
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
? |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
onclose
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
onerror
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
onmessage
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
onopen
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
open event
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
? |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
protocol
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
Supports protocol as specified by RFC 6455 | Chrome
Full support 16 |
Edge
Full support 12 |
Firefox
Full support 11 |
IE
Full support 10 |
Opera
Full support 15 |
Safari
Full support 6 |
WebView Android
Full support Yes |
Chrome Android
Full support 18 |
Firefox Android
Full support 14 |
Opera Android
Full support 14 |
Safari iOS
Full support 6 |
Samsung Internet Android
Full support 1.0 |
readyState
|
Chrome
Full support 43 |
Edge
Full support 12 |
Firefox
Full support 19 |
IE
Full support 10 |
Opera
Full support 30 |
Safari
Full support 10 |
WebView Android
Full support 43 |
Chrome Android
Full support 43 |
Firefox Android
Full support 19 |
Opera Android
Full support 30 |
Safari iOS
Full support 10 |
Samsung Internet Android
Full support 4.0 |
send
|
Chrome
Full support 4 |
Edge
Full support 12 |
Firefox Full support 18 Notes' Full support 18 Notes' Notes' See bug 775368. No support 11 — 18 Notes' Notes' Only parameter of type Notes' Notes' Only parameter of type Notes' Notes' Only parameter of type |
IE
Full support 10 |
Opera
Full support 12.1 |
Safari
Full support 5 |
WebView Android
Full support ≤37 |
Chrome Android
Full support 18 |
Firefox Android Full support 18 Notes' Full support 18 Notes' Notes' See bug 775368. No support 14 — 18 Notes' Notes' Only parameter of type Notes' Notes' Only parameter of type Notes' Notes' Only parameter of type |
Opera Android
Full support 12.1 |
Safari iOS
Full support 4.2 |
Samsung Internet Android
Full support 1.0 |
url
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox
Full support Yes |
IE
? |
Opera
Full support Yes |
Safari
Full support Yes |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
Available in workers | Chrome
Full support Yes |
Edge
Full support ≤18 |
Firefox
Full support 37 |
IE
? |
Opera
? |
Safari
? |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support 37 |
Opera Android
? |
Safari iOS
? |
Samsung Internet Android
Full support Yes |
The WebSocket API (WebSockets) by Mozilla Contributors is licensed under CC-BY-SA 2.5.