If you’ve been working with Node.js, you’ve likely encountered both npm and npx.
While they sound similar and are both integral parts of the Node.js ecosystem, they serve different purposes. This post will explore the differences between npm and npx, helping you understand when and why to use each.

What is NPM?

NPM, short for Node Package Manager, is the default package manager for Node.js. It allows developers to install, share, and manage packages (libraries or code modules) in their projects.

Here are some common tasks npm helps with:

• Installing dependencies:

npm install <package-name>

• Managing package versions: Locking down specific versions of libraries to ensure consistent builds.

• Running project-specific scripts: Defined in the package.json file.
  

npm run <script-name>

What is NPX?

npx is a tool introduced in NPM version 5.2.0 (July 2017). While npm manages dependencies and packages, npx is designed to execute Node.js packages, especially CLI tools, without globally installing them.

Key Differences Between NPM and NPX

1. Package Installation vs Execution

• NPM: When you install a package using npm, it either installs the package globally or locally to your project directory. This means you have to install a package first before you can use it.

npm install -g create-react-app
create-react-app my-app

• NPX : With npx, you can run CLI tools or executables without installing them globally. For instance, you can run create-react-app without installing it globally.

npx create-react-app my-app

This saves time and disk space as you avoid installing packages that you might only use once.

2. Global Packages
When you use npm, global packages are installed and persist across your system, which can sometimes clutter your environment.

With npx, you can execute a package without worrying about keeping it around on your system permanently.

Example of installing a package globally with npm:

npm install -g typescript
tsc --version

With npx, no global installation is necessary:

npx tsc --version

3. Automatic Package Handling
When you run a command with npx, it automatically checks if the package exists locally or globally, and if not, it downloads and executes it temporarily. This is especially useful for running one-off tasks.

For instance:

npx cowsay "Hello, World!"

This will download the cowsay package if it’s not installed, run it, and then clean up afterward.

4. Package Executables Without Scripts
When running a command defined in package.json scripts using npm, you’d write:

npm run my-script

But with npx, you can run executable commands directly:

npx my-script

This is especially useful if the script isn’t explicitly defined in package.json.

When to Use NPM

- Managing dependencies: Use npm for installing, updating, and removing project dependencies.

- Running project-specific scripts: Defined in package.json and tailored to your project.

- Managing package versions: Locking down specific versions of libraries to maintain project consistency.

When to Use NPX

- One-time package execution: Use npx for packages you don’t want to install globally, such as CLI tools you’ll only use once.

- Running executables: For commands like create-react-app, npx allows you to run them without global installation.

- Testing different versions: Quickly execute a specific version of a tool without needing to install it.

Finally,Both npm and npx are essential tools in the Node.js ecosystem, but they serve different purposes. Use npm for managing your project’s dependencies and npx for executing packages without permanent installation.

This small distinction can make your workflow more efficient, saving time and avoiding unnecessary global installations.