The WebSocket() constructor returns a new WebSocket object.

Syntax

var ws = new WebSocket("ws://localhost:8080");

Parameters

url
The URL to which to connect; this should be the URL to which the WebSocket server will respond.
protocols Optional
Either a single protocol string or an array of protocol strings. These strings are used to indicate sub-protocols, so that a single server can implement multiple WebSocket sub-protocols (for example, you might want one server to be able to handle different types of interactions depending on the specified protocol). If you don't specify a protocol string, an empty string is assumed.

Exceptions thrown

SECURITY_ERR
The port to which the connection is being attempted is being blocked.

Specifications

Specification Status Comment
HTML Living Standard
The definition of 'the WebSocket constructor' in that specification.
Living Standard  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support YesEdge ? Firefox Full support 7
Full support 7
No support 4 — 7
Notes
Notes Parameter protocols not supported.
IE ? Opera Full support YesSafari ? WebView Android ? Chrome Android Full support YesEdge Mobile ? Firefox Android Full support 7Opera Android ? Safari iOS ? Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown
See implementation notes.
See implementation notes.

Document Tags and Contributors

Contributors to this page: sideshowbarker, fscholz, Claas
Last updated by: sideshowbarker,