The WebSocket protocol is implemented in different web browsers, web servers, and run-time environments and libraries acting as clients or servers. The following is a table of different features of notable WebSocket implementations.

Client (library)Server (library)Version comparedProtocol (spec) version supportProtocol test reportLicenseImplementation: language, environmentAPI: language, environmentSelf-hosted serverText message supportBinary message supportAPI message-basedAPI frame-basedAPI streaming input-outputFlow-control frameworkAutomatic pongs for pingsAutomatic heartbeat pingsManual pings-pongsFrame size limit
Google Chrome 15YesNo15.0.874.8 12 Sep 20118 (10)ComplexC++, WebKitJavaScript, HTML5NoYesYesYesNoNo, NoNoYesNoNo≥ 16 MB (memory-limited?)
Google Chrome 16YesNo16.0.912 13 Dec 201113 (17/RFC 6455)ComplexC++, WebKitJavaScript, HTML5NoYesYesYesNoNo, NoNoYesNoNo≥ 16 MB (memory-limited?)
Mozilla Firefox 7YesNo7 beta 12 Sep 20118 (10)MPL, GPL, LGPLC++,JavaScript, HTML5NoYesNoYesNoNo, NoNoYesNoNo< 16 MB
Mozilla Firefox 11YesNo11.0 13 Mar 201213 (17/RFC 6455)MPL, GPL, LGPLC++,JavaScript, HTML5NoYesYesYesNoNo, NoNoYesNoNo< 2 GB (memory-limited?)
Achex WSYesYes2.17 17 June 2014RFC 6455CommercialC++C++, JavaScriptYesYesYesYesYesYesYesNoNoYes2^16
Kaazing WebSocket GatewayYesYes5.0 Dec 2014RFC 6455APL2 (Community Edition), commercial (Enterprise Edition)Java, JMSJavaScript, Flash/Flex, Silverlight, Objective-C & iOS, Java, Java & Android, .NET, XamarinYesYesYesYesNoYesYesYesYesNomemory-limited, configurable
LightstreamerYesYes7.4.7 12 Jun 2025RFC 6455Commercial, freewareJavaJavaScript, Android, Java, Swift, iOS, macOS, tvOS, watchOS, visionOS, .NET Standard, C++, Python, Flash/Flex, Silverlight, J2MEYesYesNoYesNoNoYesYesYesNoData driven, configurable
MigratoryDataYesYes6.0.5 29 Aug 2021RFC 6455CommercialJavaJavaScript, iOS, Android, Java, C++, .NET, PHP, Node.js, PythonYesYesNoYesNoNo, NoYesYesYesNo263, configurable
MongooseYesYes7.9 24 Jan 2023RFC 6455GPL, commercialC/C++C/C++YesYesYesYesYesYesYesYesNoYes263, configurable
noPollYesYes0.3.2 28 aug 2015RFC 6455LGPL 2.1ANSI CANSI CYesYesYesYesYesYesNoYesYesYesmemory-limited, configurable
POCO C++ LibrariesYesYes1.4.6 23 Sep 2014RFC 6455BoostC++, POCO C++ LibrariesC++YesYesYesNoYesYesNoNoNoYesmemory-limited, configurable
PowerWebSocketsYesYes15.176.5188 26 Jun 2015RFC 6455Test reportCommercial.NET.NET Framework, .NET Compact Framework, Xamarin. iOS, Xamarin.Android, Windows Phone, Silverlight, MonoYesYesYesYesNoYesYesYesYesYesmemory-limited, configurable
QtWebSocketsYesYes1.0 12 Nov 2013RFC 6455LGPLC++, QtQtYesYesYesYesYesNoYesYesYesYesmemory-limited, configurable
RingSocketNoYes1.0 13 Sep 2019RFC 6455MITCCYesYesYesYesNoNoYesYesNoNounlimited/configurable
ResinNoYes4.026 29 Feb 2012RFC 6455GPL, commercialJava, CJavaYesYesYesNoYesNoYesNoNomemory-limited, configurable
WebSocketListenerNoYes2.1.3 24 Nov 2014RFC 6455MIT.NET, Mono.NET, MonoYesYesYesYesNoYesYesYesYesNoConfigurable
WtNoYes3.2.0 30 Nov 20110,7,8,13 (17)[? Report]GPL, commercialC++, Boost AsioC++YesYesNoNoNoYesYesYesNomemory-limited, configurable
XSockets.NETYesYes5.*RFC 6455Commercial.NETServer-languages: Windows (.NET), Unix-Linux (Mono) Client-languages: JavaScript, .NET, MonoYesYesYesYesNoYesYesYesYesYesmemory-limited, configurable
RIWA GatewayYesYes2.01RFC 6455CommercialJavaJava, Android, iOS, JavaScriptYesYesYesYesNoYesNoYesNoNomemory-limited, configurable
μWebSocketsNoYesv0.14.0 28 Mar 2017RFC 6455Test reportApache License 2.0C++, epoll, Libuv, Boost AsioC++, JavaScript, Node.jsYesYesYesYesYesYesYesYesYesYesmemory-limited, configurable, server focused missing client support
Boost.BeastYesYes94 30 July 2017RFC 6455Test reportBoostC++, Boost AsioC++YesYesYesYesYesYesYesYesYesYesunlimited (packets streamed to user code), permessage-deflate also unlimited (chunked)
libwebsocketsYesYes2.4 16 Oct 2017RFC 6455 + RFC 7692Test reportLGPL2 + SLEC, libuv, libev , libevent, poll, external poll loop integration, OpenSSL, mbedTLSC, HTML5, JavaScriptYesYesYesYesYesYes, yesYesYesYesYesunlimited (packets streamed to user code), permessage-deflate also unlimited (chunked)
websocket++YesYes0.8.2 20 Apr, 2020RFC 6455BSDC++11C++11???????????
facil.ioYesYes0.7.1 18 May 2019RFC 6455MITCCYesYesYesYesYesYes, yesYesYesYesYesconfigurable client to server limits. unlimited (chunked) server to client.
oatpp-websocketYesYes1.3.0 19 Nov 2021RFC 6455Apache License 2.0C++11, Oat++C++11, Oat++YesYesYesYesYesYesYesNoNoYesunlimited (packets streamed to user code)

Notes