How to Use Nodemon in Node.js Projects

Tired of manually restarting your Node.js server every time you make a change? That’s where nodemon comes in. This guide shows you how to install and use nodemon to streamline your development process.

1. What is Nodemon?

Nodemon is a command-line tool that watches your Node.js files and automatically restarts the server whenever changes are detected. It saves time and improves your dev flow.

2. Installing Nodemon

You can install nodemon globally (accessible from anywhere) or as a dev dependency:

Global installation:

npm install -g nodemon
  

Local (project-level) installation:

npm install --save-dev nodemon
  

3. Running Your App with Nodemon

If your main file is app.js, you can start your project like this:

nodemon app.js
  

This behaves just like node app.js, but restarts automatically whenever the file changes.

4. Update Your Package.json (Optional)

You can add a custom script to your package.json to avoid typing the full command each time:

"scripts": {
  "start": "node app.js",
  "dev": "nodemon app.js"
}
  

Now run your dev server using:

npm run dev
  

5. Watch Specific Extensions (Optional)

By default, nodemon watches .js, but you can tell it to watch other types too:

nodemon --ext js,json server.js
  

6. Ignore Files (Optional)

Use a nodemon.json file to configure ignore rules:

// nodemon.json
{
  "ignore": ["temp/*", "logs/*"]
}
  

7. Nodemon + Express Example

// app.js
const express = require("express");
const app = express();

app.get("/", (req, res) => {
  res.send("Nodemon is awesome!");
});

app.listen(3000, () => {
  console.log("Server running on http://localhost:3000");
});
  

Run it using:

nodemon app.js
  

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Final Thoughts

Nodemon is a must-have tool for any Node.js developer. It simplifies the development workflow, reduces errors, and speeds up iteration. If you're not using it yet—start now!

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