Build a Real-Time Chat in 30 Minutes with WebSockets

From zero to live chat in half an hour

REST APIs poll for new data. WebSockets push it the instant it happens. Here's how to build a working chat with Node.js and Socket.io.

Step 1 — Server (10 lines)

const io = require("socket.io")(3000, { cors: { origin: "*" } });
io.on("connection", socket => {
  socket.on("message", msg => io.emit("message", msg));
});

Step 2 — Client

const socket = io("http://localhost:3000");
socket.on("message", msg => appendMessage(msg));
form.addEventListener("submit", () => socket.emit("message", input.value));

Step 3 — Add rooms

Use socket.join(room) and io.to(room).emit() to create separate channels. Add authentication middleware with io.use().

This foundation scales to notifications, live dashboards, multiplayer games, and collaborative editing. WebSockets are the gateway to real-time web development.