Getting started with fnm, a Rust-built Node.js version manager

In the web development industry, Node.js is a household name. This is because it powers everything from video streaming on Netflix to helping astronauts stay safe in space.

When it comes to installing Node.js on a development machine, you would normally install the environment using these steps:

1. First, navigate to the Node.js website and procure the latest LTS version:
   
2. The installation process differs across different OSes. For example, if you’re on Windows or macOS, run the executable installer. Alternatively, if you’re on Linux, use NodeSource to install Node on your machine:
   
3. As time goes on, you also have to manually check whether an update is available. If this is true, you would have to uninstall the previous version of Node and perform this process all over again.

You might think to yourself, “Sure, this process works for me.” However, there is a minor flaw in this process: it is too tedious and time-consuming. This is because of the following reasons:

1. Node.js doesn’t notify users when an update is available, which means that the developer has to regularly check for updates
2. Furthermore, every time an update is available, you have to reinstall Node all over again, which wastes time and energy
3. Finally, you can’t install different versions of Node on one computer. This is problematic in situations where, for example, a certain project relies on Node v 16 and another app uses Node v 18

This is where fnm comes in. It is a piece of software written in Rust that allows developers to switch between Node versions with relative ease.

In this article, you will learn about the fnm project. Here is what we’ll cover:

• What is fnm, and why you should use it?
• Installing fnm
• Managing Node.js versions with fnm
  • Listing all Node.js versions
  • Using a particular version
  • Uninstalling Node.js versions
• Setting Node.js version aliases
• Uninstalling fnm
• Alternatives to fnm
  • NVM
  • Volta

What is fnm, and why you should use it?

fnm, or Fast Node Manager, is a Node version manager that was written in Rust. Since it is a version manager, it boasts the easy installation of different Node.js versions. You can install Node via the install command:

Other than that, uninstalling is a breeze. For example, we can remove different Node versions using the uninstall command:

fnm uninstall <version> #uninstall a version of Node.js
fnm uninstall 19.3.0 #use this version of Node.js

Moreover, this project is written in Rust. This means that fnm brings speed and stability to the table.

Installing fnm

The fnm team bundles an installation script that makes downloading the software a breeze. To run this script, type this command in your terminal:

curl -fsSL https://fnm.vercel.app/install | bash

Don’t want to use the terminal? No problem! Head over to the Releases page and install their binaries.

When that’s done, verify that everything works by writing this bash command:

fnm --help

This should return this result:

This means that our installation was successful! In the next section, we will now learn how to install Node.js using fnm.

Managing Node.js versions with fnm

To download and install specific versions of Node.js, use the following syntax:

fnm install <version>

For example, this command installs 14.15.0 on the dev machine:

fnm install 14.15.0

Alternatively, if you want to use the latest version, simply use the --latest flag, like so:

fnm install --latest

This will be the result:

Otherwise, to install the lts version, just pass the --lts argument:

Listing all Node.js versions
This bash command tells fnm to list all Node versions that are available to download:

fnm ls-remote

If you want to see what versions are installed on the system, just write:

fnm list

As you can see, in my case, two Node.js versions (18 and 19) were installed on the local machine.

Using a particular version of Node.js

To use a specific version of Node, we have to run the use command. It follows this syntax:

fnm use <version>

For example, if you want your computer to switch to Node 19.3.0:

fnm use 19.3.0

We can verify that we’ve changed our version with the current command:

fnm current 

This indicates that our machine is now running Node version 19.3.0.

Uninstalling Node.js versions

To purge certain Node installations, use the uninstall keyword like so:

fnm uninstall <version>

For example, this removes Node 19.3.0 :

fnm uninstall 19.3.0 #uninstall the latest version of node

Setting Node.js version aliases

Aliases allow developers to “name” certain Node versions semantically. This is a great feature because it means that programmers don’t need to remember multiple Node versions if they’re working on many projects.

To set an alias, use this syntax:

fnm alias <version> <name> 

For example,

fnm alias 18.12.1 my-project

The above command assigns the my-project alias to Node version 18.12.1.

To verify whether our alias was successfully configured, we can re-run fnm list:

Uninstalling fnm

In some cases, developers might encounter bugs, such as command issues during development. As a result, you may have to reinstall the fnm tool to fix this. In this section, you will learn how to delete fnm from your machine.

To purge fnm, we have to first find its installation directory:

fnm env #get all environment variables

Here, the FNM_DIR variable indicates the location of fnm. As the next step, go to the path and simply remove the fnm folder like so:

#in this case, fnm was in the 'share' folder
cd $HOME/.local/share
rm -rf fnm #removing this folder will uninstall this software

And we’re done!

Alternatives to fnm

NVM

NVM (Node version manager) is an alternative to fnm that allows developers to install and manage their Node installs. Some sample commands include:

nvm use 18.15.0 #use a certain Node version
nvm install --lts #install Node to local machine

When compared to fnm, you might notice that it is far slower. Furthermore, this application doesn’t support Windows operating systems. As a workaround, The nvm team recommends nvm-windows, but it is not officially supported.

Volta

Similar to nvm, Volta is also a Node version management tool. Just like fnm, it was also built with Rust, thus bringing stability and speed to the table. Moreover, it lets creators “pin” certain Node engines. This means that if there’s a project that relies on a certain Node install, Volta will automatically switch to that Node version to prevent instability issues in the stack.

volta install node # install latest Node LTS
volta pin node@14 # tell Volta that our project will use this node version

Conclusion

Since its launch, Fast Node Manager has become the default way to install Node on my computer. Although other alternatives like nvm and Volta exist, fnm has always been my tool of choice because of its speed and simplicity.

Thank you so much for reading! Happy coding!