Socket.IO

Socket.IO is an event-driven library for real-time web applications. It enables real-time, bi-directional communication between web clients and servers.^[2] It consists of two components: a client, and a server. Both components have a nearly identical API.

Socket.IO
Original author	Guillermo Rauch
Developer	Automattic
Stable release	4.7.5  / 14 March 2024; 19 months ago (14 March 2024)
Repository	github.com/socketio/socket.io
Written in	JavaScript
Operating system	Cross-platform
Type	Event-driven networking
License	MIT License[1]
Website	socket.io

Socket.IO is also a protocol,^[3] where different complying implementations of the protocol can communicate with each other. The main implementation consists of two parts: a client that runs in the browser and a server for Node.js. Apart from the main implementation, there are multiple implementations, for example, the official Deno (JavaScript), C++, Java, Python, and Swift servers.

Socket.IO primarily uses the WebSocket protocol with polling as a fallback option, while providing the same interface.^[4] Although it can be used simply as a wrapper for WebSockets, it provides many additional features such as heartbeats and timeouts.^[4]

It can be installed with the npm (Node Package Manager).^[5]

See also

• Free and open-source software portal

• JavaScript framework
• JavaScript library
• SignalR