Environment Variables in Node.js

Environment Variables in Node.js — a practical guide to Node.js environment variables with clear examples you can reuse in real projects.

Environment Variables in Node.js — 49/55 in the Node.js series. Full playlist companion: Node.js complete course on YouTube. Prefer one article? Read the complete Node.js tutorial.

Short description

Environment variables keep secrets out of source code. Use `.env` locally and real env vars in production.

dotenv example

// npm i dotenv
require('dotenv').config();

const port = process.env.PORT || 3000;
const mongoUrl = process.env.MONGO_URL;
console.log({ port, mongoUrl: Boolean(mongoUrl) });