What is Express?

A Minimal, Unopinionated Node Web Framework

What is Express?

Express is the most-used Node web framework. A thin layer on top of node:http with routing, middleware, and helpers.

3 min read Level 1/5 #express#intro#framework
What you'll learn
  • Know what Express is and isn't
  • Place it next to Fastify, NestJS, Hono
  • Know the version landscape

Express is a small, unopinionated web framework for Node.js. It adds three big things on top of the built-in node:http module:

  1. Routingapp.get("/users/:id", handler)
  2. Middleware — a chain of functions every request flows through
  3. Helpersres.json(), res.redirect(), req.params, etc.

That’s basically it. The reason it dominates the Node ecosystem is not feature count — it’s minimalism. Express stays out of your way and lets you build APIs or full-stack apps your own way.

What You’ll Build

By the end of this track, you’ll be comfortable:

  • Routing complex URLs (params, regex, nested resources)
  • Composing middleware for auth, validation, logging
  • Building REST APIs that follow real-world conventions
  • Adding sessions, JWT, Passport — picking the right auth model
  • Integrating databases, file uploads, WebSockets
  • Testing, logging, monitoring, deploying

Why Express, Why Now

Despite being 14+ years old, Express is still the default for Node web apps. Reasons:

  • Tiny core, huge ecosystem
  • Stable API — code from 2018 still works
  • Express 5 added async error handling and modern routing without breaking everything
  • Most Node tutorials, Stack Overflow answers, and job postings assume it

Alternatives worth knowing:

FrameworkPitch
FastifyFaster, schema-driven, modern API
NestJSOpinionated, decorator-based, TypeScript-first
HonoTiny, web-standards-first, runs on edge runtimes
KoaExpress’s spiritual successor, smaller core

We touch these at the end. For ~80% of Node jobs and projects in the wild, Express is what you’ll use.

What This Track Assumes

  • You can write modern JavaScript (let, const, async/await, modules)
  • You’ve installed Node 20+ and run a script

If not, the JavaScript and Node.js tracks come first.

Up Next

Install Express and ship a working server.

Installing Express →