# nvm — Fast Node Version Manager for POSIX Shells

> Install and switch between multiple Node.js versions effortlessly with nvm, the most popular shell-based version manager for Node.js.

## Install

Save as a script file and run:

# nvm — Fast Node Version Manager for POSIX Shells

## Quick Use
```bash
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash
nvm install --lts
nvm use 20
```

## Introduction
nvm (Node Version Manager) is a POSIX-compliant shell script that lets you install and manage multiple active Node.js versions on a single machine. It is the de-facto standard for switching Node runtimes across projects without polluting global paths.

## What nvm Does
- Installs any published Node.js version with a single command
- Switches the active Node version per terminal session
- Reads `.nvmrc` files to auto-select the correct version per project
- Keeps each version's global npm packages isolated
- Works on macOS, Linux, and WSL without root privileges

## Architecture Overview
nvm is implemented entirely in shell script (bash/zsh compatible). It manipulates the `PATH` environment variable to point at a versioned Node.js install directory under `~/.nvm/versions/node/`. When you run `nvm use`, it simply re-prefixes your PATH so that the chosen binary directory comes first. No daemon or background service is involved.

## Self-Hosting & Configuration
- Install via the official curl one-liner that appends nvm init to your shell profile
- Set `NVM_DIR` to customize the install location (default `~/.nvm`)
- Create a `.nvmrc` file per project containing just a version string like `20` or `lts/iron`
- Run `nvm alias default <version>` to set the version for new shells
- Use `nvm install-latest-npm` after switching to ensure npm is current

## Key Features
- Zero-dependency pure shell script with no compiled binaries
- Supports LTS aliases (`--lts`, `lts/hydrogen`) for convenience
- Per-project version pinning via `.nvmrc`
- Tab completion for bash and zsh
- Can install from source with `nvm install -s <version>`

## Comparison with Similar Tools
- **fnm** — written in Rust for faster startup; nvm has broader adoption and longer track record
- **asdf** — multi-language version manager; nvm is Node-specific with deeper Node ecosystem integration
- **Volta** — handles package binaries and pinning in `package.json`; nvm is simpler and shell-native
- **n** — interactively manages Node versions globally; nvm provides per-shell isolation
- **mise** — polyglot dev tool manager; nvm remains the most widely documented choice for Node

## FAQ
**Q: Does nvm work on Windows natively?**
A: No. nvm is a POSIX shell script. On Windows, use WSL or the separate nvm-windows project which is a different codebase.

**Q: How do I auto-switch Node versions when I cd into a project?**
A: Add `nvm use` to a shell hook or enable deeper shell integration (e.g., the `cdnvm` snippet from the README) that reads `.nvmrc` on directory change.

**Q: Does switching versions affect globally installed npm packages?**
A: Yes. Each Node version has its own global `node_modules`. Use `nvm reinstall-packages <old-version>` to migrate them.

**Q: Can I use nvm in CI/CD pipelines?**
A: Yes, but many CI services pre-install Node via other means. Source `nvm.sh` in your CI script and call `nvm install` to set the version from `.nvmrc`.

## Sources
- https://github.com/nvm-sh/nvm
- https://github.com/nvm-sh/nvm#readme

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Source: https://tokrepo.com/en/workflows/9e40347a-40e3-11f1-9bc6-00163e2b0d79
Author: Script Depot