Overview

fnm is a Node.js version manager built in Rust for developers who manage Node versions from the command line. Its project-file support and shell integrations make it a strong fit for switching versions across projects; it is less suited to anyone seeking a manager for multiple languages.

Key features

fnm can use .node-version and .nvmrc files to pin a project’s Node.js version. With shell setup enabled, it can switch versions automatically as you move between directories, sparing developers from having to select the right version manually for each project.

Shell integration instructions cover Bash, Zsh, Fish, PowerShell, Windows Command Prompt, and Cmder. The binary also includes completions for Bash, Zsh, Fish, and PowerShell. That breadth is useful for teams and individuals working across different shells, though Command Prompt and Cmder are not among the shells with listed completions.

fnm is distributed as a single file, with installation options including scripts, package managers, Cargo, and release binaries. The macOS and Linux installation script requires curl and unzip; users without those utilities can choose another distribution method.

Pricing

fnm is free, at 0.00 USD per free, with no paid plans. There is no trial to evaluate because the free plan has no stated end date. That removes a subscription decision for individual developers, but does not imply paid support or other commercial terms.

Platforms

fnm supports macOS, Windows, and Linux. Its cross-platform reach is a practical advantage for developers moving among those systems, while the installation-script prerequisite applies specifically to macOS and Linux script installs.

Who it's for

Choose fnm if you work with Node.js projects that pin versions in `.node-version` or `.nvmrc` files and want shell-based automatic switching. Its scope is a single language, so developers who need one tool to manage versions across several languages should look at a broader environment manager instead.

Pros and cons

Pros: Project-file support and automatic directory-based switching help keep the active Node.js version aligned with each project.
Pros: macOS, Windows, and Linux support, plus integrations for several shells, suit varied developer setups.
Pros: Free with no paid plans, and distributed through several installation routes.
Cons: It manages Node.js rather than multiple language runtimes, limiting its usefulness as a general development environment manager.
Cons: The macOS and Linux installation script depends on `curl` and `unzip`.
Cons: The project has no SECURITY.md file, even though its page reports no published security advisories; teams that require a documented security policy may prefer a project with one.

Alternatives

For a similar free Node.js version manager, consider nvm, which supports Linux, macOS, Windows, and self-hosted use. Choose a cross-language tool if managing more than Node.js is the priority: asdf is a free open-source tool version manager, while Development Environment Managers is a broader category to compare.

For a runtime other than Node.js, rustup is a free option supporting Linux, macOS, and Windows; elan is a free Lean version manager. Go developers can consider GVM, which supports Linux and macOS, or goenv, a free Go version manager for those platforms. PHPBrew is a free option for PHP on Linux and macOS, but building PHP requires development packages and unsupported older PHP versions may fail to build. RVM is another alternative.

Browse Runtime Version Managers for more options.

Verdict

For Node.js developers who want project-pinned versions and automatic shell switching across macOS, Windows, and Linux, fnm is a compelling free choice. Look elsewhere if you need one manager for several languages or require a project with a published security policy.

	fnm	MAMP
Free plan	Yes	No
Free trial	No	No
Paid from	Free	—
Open source	No	No
Platforms	Linux, macOS, Windows	Windows, macOS
Free plan	Yes	Yes
Supported scope	single_language	—
Project version pinning	Yes	—
Automatic switching	Yes	—
Shell integration	Yes	—
Operating systems	cross_platform	—

fnm vs MAMP

fnm

MAMP