Where does NPM Install the packages ?

npm is the default package manager for Node.js, and it is used to install, manage, and distribute JavaScript packages. When you install a package using npm, it can be installed either locally or globally. The location where npm installs the package depends on the installation method you use.

When you install a package locally, it is placed in the node_modules directory within your project folder. This means the package is available only to that specific project and not accessible globally.

How to Install Locally

To install a package locally, you typically run:

npm install <package-name>
npm i <package-name>  #shorthand

For example, to install the express package locally, you would run:

npm install express

Location of Installed Packages

The packages are installed in the node_modules directory within your project folder, and the dependencies are listed in the package.json file. For instance, if your project structure is:

/my-project
  |-- package.json
  |-- node_modules/
  |   |-- express/

The express package will be installed in /my-project/node_modules/express.

Benefits of Local Installation

• Project-Specific: Dependencies are specific to the project, avoiding conflicts with other projects.
• Easier Version Control: You can easily manage different versions of packages for different projects.
• Portable: The entire project, including its dependencies, can be easily shared or moved.

When you install a package globally, it is placed in a system-wide directory and made available from any location on your system. This is useful for installing tools and utilities that you want to use across multiple projects.

How to Install Globally

To install a package globally, use the -g or --global flag:

npm install -g <package-name>

For example, to install the nodemon package globally, you would run:

npm install -g express

To List all the Global Packages in the system

npm list -g --depth 0 

Output:

Location of Installed Packages

The location of globally installed packages depends on your operating system and npm configuration:

• Windows: Packages are installed in %APPDATA%\npm\node_modules.
• macOS and Linux: Packages are typically installed in /usr/local/lib/node_modules or a user-specific directory like ~/.npm-global.

You can find the exact location by running:

npm root -g

Benefits of Global Installation

• Accessible Everywhere: Packages are available system-wide and can be used in any project.
• Convenient for CLI Tools: Ideal for installing command-line tools that you use frequently.

• Permission Issues: On Unix-like systems, you might encounter permission issues when installing globally. You can resolve this by configuring a custom directory for global installations as mentioned above.
• Version Conflicts: Different projects might require different versions of a package. Use local installations to isolate dependencies.
• Path Not Found: If globally installed packages are not found in the path, ensure your system’s PATH variable includes the global npm directory.

Understanding where npm installs packages is crucial for effective dependency management in Node.js projects. Local installations ensure project-specific dependencies, while global installations are ideal for tools and utilities that you use across projects. By mastering these installation methods, you can manage your Node.js projects more efficiently, avoid conflicts, and streamline your development workflow.