Open Source Go WebSocket Servers

GoWebSocket is a Go-based distributed WebSocket chat and instant messaging system designed around very high connection counts. It demonstrates how to build a scalable IM architecture using Go, Gin, Nginx load balancing, horizontal deployment, and internal service communication. The project uses gRPC for communication between program components and is structured to support distributed real-time messaging rather than a single-process chat demo. Its documentation highlights single-machine million-connection goals, making performance and concurrency central to the design. gowebsocket is useful for developers studying large-scale WebSocket systems, chat backends, connection management, and Go network programming. It is best treated as a technical reference and learning project for distributed real-time architecture.

We wanted a simple server for sending and receiving messages (in real time per WebSocket). For this, not many open source projects existed and most of the existing ones were abandoned. Also, a requirement was that it can be self-hosted. We know there are many free and commercial push services out there. Both Gotify's API and user interface are designed to be as simple as possible. Notify is written in Go and can be easily compiled for different platforms. Docker images are automatically built on every release. Several static code analyzers and many unit/end2end tests are run on every travis-ci build. The heart of this project. gotify/server features a WebUI and functionality for sending messages via a REST-API. For subscribing/receiving messages via a web socket connection and managing users, clients and applications.

GWS is a high-performance WebSocket library for Go that provides both server and client capabilities. It is designed for high-concurrency use cases such as API gateways, chat systems, reverse proxies, online games, real-time streaming, and push or subscription services. The library exposes a minimal event-driven API, allowing developers to build WebSocket applications with relatively little code. It supports standard TCP usage as well as WebSocket operation over KCP and Unix domain sockets. GWS also includes practical features for connection handling, compression, heartbeat management, UTF-8 validation, and scalable read or write loops. It is a strong fit for Go developers who need a lightweight but feature-complete WebSocket foundation for real-time applications.

Gorilla WebSocket is a Go implementation of the WebSocket protocol. The Gorilla WebSocket package provides a complete and tested implementation of the WebSocket protocol. The package API is stable. An application can also send and receive messages using the io.WriteCloser and io.Reader interfaces. To send a message, call the connection NextWriter method to get an io.WriteCloser, write the message to the writer and close the writer when done. To receive a message, call the connection NextReader method to get an io.Reader and read until io.EOF is returned. The WebSocket protocol distinguishes between text and binary data messages. Text messages are interpreted as UTF-8 encoded text. The interpretation of binary messages is left to the application. The Gorilla WebSocket package passes the server tests in the Autobahn Test Suite using the application in the examples/autobahn subdirectory.

Melody is a minimalist WebSocket framework for Go that wraps the standard WebSocket workflow in a simple, developer-friendly API. It is designed to make real-time server features easier to build without requiring a large framework or complex setup. Developers can use it for chat systems, live notifications, dashboards, multiplayer coordination, collaborative tools, and other bidirectional communication features. Melody provides connection lifecycle hooks, message handlers, broadcasting, session management, and grouped communication patterns. It is built to feel familiar to Go developers and can be integrated into existing HTTP applications. The project is especially useful when a team needs straightforward WebSocket behavior without building connection handling and broadcast logic from scratch.

Gev is a lightweight, fast non-blocking TCP network library / websocket server based on Reactor mode. Support custom protocols to quickly and easily build high-performance servers. Support custom protocols to quickly and easily build high-performance servers. High-performance event loop based on epoll and kqueue. Support multi-core and multi-threading. Dynamic expansion of read and write buffers implemented by Ring Buffer. Asynchronous read and write. SO_REUSEPORT port reuse support. Automatically clean up idle connections. Support WebSocket/Protobuf, custom protocols. Support for scheduled tasks and delayed tasks. High-performance web socket server.

go-socket.io is the library implementation of Socket.IO in Golang, which is a real-time application framework. Current this library supports 1.4 version of the Socket.IO client. It supports room, namespaces and broadcast at now. This project is looking for contributors to help fix bugs and implement new features.

websocket is a minimal and idiomatic WebSocket library for Go. Minimal and idiomatic API. First class context.Context support. Fully passes the WebSocket autobahn-testsuite. Single dependency. JSON and protobuf helpers in the wsjson and wspb subpackages. Zero alloc reads and writes. Concurrent writes. Close handshake. net.Conn wrapper. Ping pong API. RFC 7692 permessage-deflate compression. Compile to Wasm. Transparent message buffer reuse with wsjson and wspb subpackages. Gorilla writes directly to a net.Conn and so duplicates features of net/http.Client. Gorilla requires registering a pong callback before sending a Ping. Compare godoc of nhooyr.io/websocket with gorilla/websocket side by side. Will enable easy HTTP/2 support in the future.

websocketd is the WebSocket daemon. It takes care of handling the WebSocket connections, launching your programs to handle the WebSockets, and passing messages between programs and web-browser. If you can run your program from the command line, you can write WebSocket endpoints. Just read incoming text from stdin and write outgoing text to stdout. Messaging is simple. Each inbound WebSocket connection runs your program in a dedicated process. Connections are isolated by process. Available for Linux, OSX, Windows, FreeBSD, OpenBSD and Solaris. Serves your static HTML, JavaScript, etc. Route different URLs to different programs. Dynamic generate content over HTTP too. Out-of-the-box support for serving content using HTTPS and WSS. Restrict which pages can make WebSocket connections. Interact with your WebSocket programs before you've built your frontend.

Zero-copy upgrade. No intermediate allocations during I/O. Low-level API which allows building your own logic of packet handling and buffers reuse. High-level wrappers and helpers around API in wsutil package, which allow to start fast without digging the protocol internals. Existing WebSocket implementations do not allow users to reuse I/O buffers between connections in clear way. This library aims to export efficient low-level interface for working with the protocol without forcing only one way it could be used. Library is tagged as v1* so its API must not be broken during some improvements or refactoring. Example applications using ws are developed in separate repository ws-examples. We can apply the same pattern to read and write structured responses through a JSON encoder and decoder.Zero-copy upgrade helps to avoid unnecessary allocations and copying while handling HTTP Upgrade request.