Express Introduction

Express is a small, flexible web framework for Node.js. It handles routing, requests, responses, and middleware, so you write far less code than with the raw http module.

What Express gives you

• Routing — clean mapping of URLs and HTTP methods to handlers.
• Middleware — a pipeline for auth, logging, parsing, and more.
• Request/response helpers — res.json(), req.params, and friends.
• A huge ecosystem of middleware packages for almost anything.

Unopinionated by design

Express gives you the essentials and stays out of the way — you choose your database, structure, and libraries. That flexibility makes it great to learn on and a common foundation for larger frameworks (including NestJS).

The raw http module vs Express

Remember the manual routing and body-parsing from the Node HTTP chapter? Express replaces all of that with a few clean lines.

app.get("/users/:id", (req, res) => {
  res.json({ id: req.params.id });   // routing, params, JSON - all handled
});

Express vs alternatives

Express is the most popular and best-documented Node framework. Fastify is a faster, more modern alternative with built-in validation; NestJS adds structure on top (often on Express). Express remains the best starting point.