`µWS` is one of the most lightweight, efficient & scalable WebSocket server implementations available. It features an easy-to-use, fully async object-oriented interface and scales to millions of connections using only a fraction of memory compared to the competition. License is zlib/libpng (very permissive & suits commercial applications).

• Linux, OS X & Windows support.
• Chrome, Safari, Firefox, Edge support.
• Keep one thread per CPU core, each serving millions of connections.
• Expose a port range or use the load balancer to only expose one port, scaling over all CPU cores.
• Planned SSL/TLS support (work in progress)
• Node.js bindings are planned and will target the ws interface.

Project is a work in progress, initial commit was 21 March, 2016. I'm planning to release something in a month or less.

Benchmarks table

Implementation	Memory scaling	Connection performance	Short message throughput	Huge message throughput
libwebsockets master(1.7-1.8)	µWS is 14x as lightweight	µWS is equal in performance	µWS is 3x as performant	µWS is equal in performance
ws v1.0.1 + binary addons	µWS is 52x as lightweight	µWS is 21x as performant	µWS is 23x as performant	µWS is 2x as performant
WebSocket++ v0.7.0	µWS is 63x as lightweight	µWS is 5x as performant	µWS is 2x as performant	µWS is 3x as performant
Benchmarks are run with default settings in all libraries, except for ws which is run with the native performance addons.

Overview

int main()
{
    /* this is an echo server that properly passes every supported Autobahn test */
    uWS::Server server(3000);
    server.onConnection([](uWS::Socket socket) {
        cout << "[Connection] clients: " << ++connections << endl;
    });

    server.onMessage([](uWS::Socket socket, const char *message, size_t length, uWS::OpCode opCode) {
        socket.send((char *) message, length, opCode);
    });

    server.onDisconnection([](uWS::Socket socket) {
        cout << "[Disconnection] clients: " << --connections << endl;
    });

    server.run();
}

Quality control

• Valgrind clean
• Autobahn chapters 1 - 9 all pass.
• Small & efficient code base.

Installation

Unix

• First install the dependencies (openssl, libuv)
• git clone https://github.com/alexhultman/uWebSockets.git && cd uWebSockets
• make
• sudo make install

This will install to /usr/lib64 and /usr/include.

Windows

todo