What is Express.js and why use it over plain Node.js

Express.js vs Plain Node.js

Express.js is a minimal, unopinionated web framework for Node.js. It wraps Node's built-in http module and adds routing, middleware support, and a cleaner API — without forcing a project structure on you.

With raw Node.js, handling a single route requires parsing the URL manually, setting headers explicitly, and managing every edge case yourself. Express reduces this to one line per route.

Plain Node.js HTTP server

const http = require('http');
const server = http.createServer((req, res) => {
  if (req.url === '/hello' && req.method === 'GET') {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('Hello World');
  } else {
    res.writeHead(404);
    res.end('Not Found');
  }
});
server.listen(3000);

Same server with Express

const express = require('express');
const app = express();

app.get('/hello', (req, res) => {
  res.send('Hello World');
});

app.listen(3000);

Express handles status codes, content-type headers, and 404 fallbacks automatically. Install it with npm install express. The app object is your entry point for everything — routes, middleware, and server config.