How to Create an HTTP Server in Node.js From Scratch

How to Create an HTTP Server in Node.js From Scratch

Creating an HTTP server is the first step of Node.js backend development. Here is how to do it from scratch.

Use the Built-in http Module

Node.js has a built-in http module for creating servers. Import it with require('http'), call http.createServer with a request listener, and listen on a port. This is the foundation before Express.

The Request Listener

The listener is a function that receives request and response. The request has the URL, method, and headers. The response is what you send back: status code, headers, and body.

Sending a Response

Call response.writeHead with a status code and headers, then response.end with the body. For JSON APIs, set Content-Type to application/json and send a JSON string.

Handling Different Routes

Check request.url and request.method to handle different routes. If url is '/api/users' and method is 'GET', send the users. This is manual routing, which Express makes easier, but it teaches how servers work.

Starting the Server

Call server.listen(port) to start listening on a port. Visit http://localhost:3000 in a browser to see your server respond.

Why Start With the http Module

Building a server with the raw http module teaches how request handling, routing, and responses work. Express abstracts this, but understanding the raw module makes Express more meaningful.

The Takeaway

Create an HTTP server with require('http'), http.createServer with a request listener, send responses with writeHead and end, handle routes by checking url and method, and listen on a port. This is the foundation of Node.js backend development.