How to Use HTTPS in Node.js: Simple Guide with Example

To use https in Node.js, import the built-in https module and create a server with SSL certificate and key files. Use https.createServer(options, requestListener) where options includes your SSL credentials, then listen on a port to serve secure requests.

Syntax

The https.createServer() method creates an HTTPS server. It requires an options object containing your SSL key and cert, and a requestListener function to handle incoming requests.

• options: An object with key and cert properties holding your SSL private key and certificate.
• requestListener: A function with request and response parameters to respond to client requests.

After creating the server, call server.listen(port) to start listening for HTTPS requests.

javascript

const https = require('https');
const fs = require('fs');

const options = {
  key: fs.readFileSync('path/to/private-key.pem'),
  cert: fs.readFileSync('path/to/certificate.pem')
};

const server = https.createServer(options, (req, res) => {
  res.writeHead(200);
  res.end('Hello HTTPS!');
});

server.listen(443, () => {
  console.log('HTTPS server running on port 443');
});

Example

This example shows a simple HTTPS server that responds with "Hello HTTPS!" to every request. It uses self-signed SSL certificate files named server.key and server.cert in the same folder.

javascript

import https from 'https';
import fs from 'fs';

const options = {
  key: fs.readFileSync('./server.key'),
  cert: fs.readFileSync('./server.cert')
};

const server = https.createServer(options, (req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('Hello HTTPS!');
});

server.listen(8443, () => {
  console.log('HTTPS server running on https://localhost:8443');
});

Output

HTTPS server running on https://localhost:8443

Common Pitfalls

Common mistakes when using HTTPS in Node.js include:

• Not providing valid SSL key and cert files, causing server errors.
• Using HTTP ports (like 80) instead of HTTPS ports (like 443 or custom 8443) without proper redirection.
• Forgetting to handle errors on the server, which can crash the app.
• Using self-signed certificates in production without proper trust setup, causing browser warnings.

Always ensure your SSL files are correct and your server listens on the right port.

javascript

/* Wrong: Missing SSL options */
// https.createServer((req, res) => {
//   res.end('No SSL');
// }).listen(443);

/* Right: Provide SSL options */
const https = require('https');
const fs = require('fs');

const options = {
  key: fs.readFileSync('key.pem'),
  cert: fs.readFileSync('cert.pem')
};

https.createServer(options, (req, res) => {
  res.end('Secure!');
}).listen(443);

Quick Reference

Remember these key points when using HTTPS in Node.js:

• Use https.createServer(options, handler) with SSL key and cert.
• Listen on port 443 or a custom port for HTTPS.
• Use fs.readFileSync to load SSL files synchronously before server start.
• Handle errors to avoid crashes.
• For development, self-signed certificates are fine; for production, use trusted certificates.

Key Takeaways

Use the built-in https module with SSL key and certificate files to create a secure server.

Always provide valid SSL credentials in the options object when calling https.createServer.

Listen on port 443 or another HTTPS port to serve secure requests.

Self-signed certificates cause browser warnings; use trusted certificates in production.

Handle server errors to keep your HTTPS server stable.