How to Build a Chat App with WebSockets

Beyond HTTP

HTTP is a request-response protocol. For real-time applications like chat or live dashboards, HTTP polling is inefficient. WebSockets provide a persistent, bi-directional connection between the client and server.

Using Socket.io

Socket.io is the standard library for WebSockets in Node.js. It handles connection fallbacks (long-polling) if WebSockets aren't supported, and provides simple event broadcasting.

Scaling WebSockets

WebSockets are stateful. If you have multiple chat servers behind a load balancer, you need a Redis pub/sub adapter to ensure messages are routed to the correct server.