HTTP Module

http is Node.js's built-in module that lets it act as a web server, accepting requests and sending back responses. Before you reach for Express.js, this module is the best foundation for understanding the HTTP request/response flow.

javascript

const http = require('http');

const server = http.createServer((req, res) => {
  res.setHeader('Content-Type', 'text/html; charset=utf-8');

  if (req.url === '/') {
    res.statusCode = 200;
    res.end('<h1>Home Page</h1><p>Welcome to Node.js.</p>');
  } else if (req.url === '/about') {
    res.statusCode = 200;
    res.end('<h1>About Page</h1><p>This page is served by Node.js.</p>');
  } else {
    res.statusCode = 404;
    res.end('<h1>404 Not Found</h1>');
  }
});

server.listen(5000, () => {
  console.log('Server is listening on http://localhost:5000');
});

req.url shows the path the user requested. / returns the home page, and /about returns the about page. If nothing matches, it returns a 404 status code with a not-found message.

You should see

Server is listening on http://localhost:5000 Browser: http://localhost:5000/about About Page

Info

Returning the correct status code matters a lot for API/web server quality. Use 200 for success, 201 for created, 404 for not found, and 500 for server errors, and so on.