Lesson Overview

In this lesson you'll install Node.js on your local machine and test it to make sure everything is working.


You will need to know what operating system you have, you should be familiar with installing and running applications, and you should be able to follow instructions for installing software.

You will also need an editor where you can write programs and run them: I will be using VS Code (opens in a new tab/window).

Installing Node.js Locally

You should install Node.js locally on your computer so you can code, test, and debug your applications before uploading them to a server. Debugging on the server can be cumbersome and difficult, but you also don't want to increase the load of your server by using it to test and debug an application!

First, download the pre-build installer for the LTS (Latest Stable Version) of Node.js: Node.js Download Page (opens in a new tab/window).

download page - prebuilt instalter tab
Download the pre-built installer for your operating system

Make sure you choose the download that is most appropriate for your computer's operating system.

Running the Installer

Once you've downloaded an installer, run it. These next instructions will take you step-by-step through the installer screens. NOTE that my screen shots are for a Windows 10 system and I was installing version 18. Yours may be different and this may result in slight differences in the screen shots.

  1. Welcome screen: click NEXT
    welcome screen
    Click NEXT on the Welcome screen
  2. On the license screen, check the "I accept..." checkbox and click NEXT.
    license screen
    Accept the agreement and click NEXT
  3. The next screen asks you to choose a destination folder for the installation. Accept the default unless there's some specific reason why you can't. Make note of the destination folder location in case you need to find it later.

    TIP: if you forget and need to know, type which node in your computer's command prompt window.

    destination folder screen
    Accept the default destination folder and click NEXT
  4. The custom setup screen can be left alone, just click NEXT
    custom setup screen
    Accept the defaults and click NEXT
  5. The Tools for Native Modules screen has a checkbox to "Automatically install the necessary tools...". Make sure this is CHECKED, and then click NEXT.
    tools for native modules screen
    CHECK the checkbox and click NEXT
  6. The next screen indicates that you are ready to proceed with the installation. Click the INSTALL button.
    Ready to install screen
    Click INSTALL to proceed
  7. After the installation has completed, you should see the finishing screen: click FINISH.
    last screen
    Click FINISH on the last screen
  8. Now a command prompt window will open automatically telling you that it is about to execute a script that installs some extra tools needed to build Node.js programs. Don't do anything yet: read the rest of this instruction, first.

    Before doing anything else, make sure your current Windows installation is up to date.

    The script will take some time, and you might see lots of text and messages appear in your command prompt window.

    When you're ready, close all open programs, including your browser. If you have any issues while the script is running, reboot your computer and then try running the script again by going to your Start Menu > Node.js > Install Additional Tools for Node.js.

    After the script has finished, Reboot Your Computer. Then return to this page, for the next instruction.

    You may now start the script by pressing any key while inside the Command Prompt window. PRESS THE KEY ONLY ONCE. It will seem at first like it's doing nothing, that's normal. Just be patient.

    the command prompt window
    Read and follow all the instructions before starting the script

Test Your Installation

After you reboot your computer, test your installation:

  1. Open a Command Prompt window (e.g. search for Command Prompt in the start menu).
  2. A the prompt, type node -v and then press the ENTER key. You should see the current Node.js version appear on the screen.

    If there were any problems, go back and check the installation instructions and make sure you did everything correctly. Also, check the Node.js installation directory and see if there are files in it. If you have any issues that you can't solve, ask your professor, and be sure to provide details (error messages, screen shots, etc).

  3. Now type npm -v and press the ENTER key. You should see the current version of the Node Package Manager.
    testing installation in the command prompt window
    My current Node.js version when I took this screen shot was 18.16.0, yours is probably newer

    If there were any problems, go back and check the installation instructions and make sure you did everything correctly. Also, check the Node.js installation directory and see if there are files in it. If you have any issues that you can't solve, ask your professor, and be sure to provide details (error messages, screen shots, etc).

Writing and Running a Test Application

Let's create a test application that we can run. I'm using VS Code, which comes with a terminal we can use to run Node.js programs. If your editor doesn't have a terminal, you can simply use your operating system's Command Prompt application.

Open up your editor and create a project directory for this test project e.g. /testapp.

Add a new JavaScript file called app.js and add the following code:

// app.js

// Load HTTP module
const http = require("http");

const hostname = "";
const port = 3000;

// Create HTTP server
const server = http.createServer(function (req, res) {
  // Set the response HTTP header with HTTP status and Content type
  res.writeHead(200, { 
    "Content-Type": "text/plain" 

  // Send the response body "Hello World"
  res.end("Hello World\n");

// Prints a log once the server starts listening
server.listen(port, hostname, function () {
  console.log(`Server running at http://${hostname}:${port}/`);

Save your app.js file and then open a Terminal window (in VS Code, File > View > Terminal, or press and hold CTRL and then press the ` (backtick) key).

In VS Code, mine defaults to PowerShell, but we want the Command Prompt: press the v-shaped icon button to the right of the word "PowerShell" and then select "Command Prompt".

opening the vs code terminal
Open the VS Code Terminal

If you want, you can delete the PowerShell terminal window by pressing the Delete (trash can) button on the far right, beside the "powershell" item. Do this AFTER you have opened a Command Prompt terminal window.

removing the default powershell terminal
Open the VS Code Terminal

Make sure the prompt in your Command Prompt terminal window shows the current location of the project you're working on. If not, you can use the cd command to change directories.

We will now use the npm init command to initialize your application. Make sure you're in the same directory as your app.js file.

At the prompt, type
npm init
and then press the ENTER key.

typing npm init in the terminal
Type "npm init" in your terminal window

Running npm init initializes your app and sets it up by asking you several questions about your application. For any question, you can press ENTER to accept default, which is displayed with the question in parentheses.

Here's are some suggested answers for this test application:

Package name: the default is fine, change the name if you want
Version: the default is fine
Description: my first node.js program (or whatever you want, or just accept the default) then press ENTER
Entry point: this should default whatever you named your JavaScript file (e.g. "app.js"); if it's something different, make sure that it's the name of the javascript file
Test Command: leave blank
Git Repository: leave blank
Keywords: can leave blank
Author: your first and last name
License: accept default

answering some of the questions when initializing the app
Answer the questions for your application

When you're done, it will show a JSON object on the screen containing all the information you entered. Instructions will appear in case you need to go back and change anything (type n and then press ENTER if you want to change anything: you'll have to restart by typing npm init again), otherwise type y and press ENTER to accept everything you entered.

json data with your app settings
Your answers are saved as a JSON object

Now examine the contents of your project's directory: you'll notice a new file called package.json. If you open it, you'll see it contains the JSON data you saw in the terminal after you finished initializing your application.

the package.json file
The package.json file

The package.json file defines the properties of the application and its project. This file always lives in your project root directory. The NPM tool needs this file when you want to add packages to your project. You'll learn about this in a later tutorial.

Now that your project is set up, you can run it locally by typing:
node app
Make sure "app" is the root name of your JavaScript file. If you named your JavaScript file "main.js", then you'd type node main. The file extension is not necessary.

you should now see something similar to the following in your terminal window:

Server running at
running the app in the terminal window
Output after running the application in the terminal

Now go to your browser, open a new tab/window, and type:

You should see "Hello World" in your browser!

viewing the browser output Hello World
Browser output after running the application

If you reached this point without any problems, your application is working and Node.js has been installed correctly. You can now stop your application by pressing Ctrl-C in your terminal window.

Running an App Using Nodemon

As you code Node.js programs, you will likely find it annoying to repeatedly stop and restart the app after making changes to your code. If you want, you can install the Nodemon dependency: it will automatically save and restart your app when you make changes.

You can install Nodemon locally (for a single application) or globally (for all applications you write on the system).

Global Installation

  1. Go into your directory where your projects are.
  2. Type: npm install nodemon -g
  3. When you want to run a program, type nodemon app.js.

Local Installation

  1. Go into the project's root directory and type:
    npm install nodemon --save-dev
    this installs it as a development-only dependency for this particular project
  2. Edit the package.json file for the project
  3. Find the "scripts" item and modify it by adding the "start" key with the value nodemon app.js:
    scripts" : {
      "test" : "...",
      "start": "nodemon app.js"

    Don't forget to include the comma after the "test" statement, if it's not already there.

  4. Save the package.json file
  5. To run the program, use npm start instead of "node app"