fnm (Fast Node Manager)
Fast Node.js version manager written in Rust. Compatible with .nvmrc and .node-version files. Installs in milliseconds vs nvm's seconds. Supports bash, zsh, fish, PowerShell, and Windows Command Prompt. Designed as a drop-in nvm replacement that's orders of magnitude faster with cross-platform support.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Rust implementation with memory safety. HTTPS downloads from official Node.js CDN. No credentials needed. Open source and auditable.
⚡ Reliability
Best When
You want a fast, nvm-compatible Node.js version manager that works on Windows, Mac, and Linux with your existing .nvmrc files.
Avoid When
You need package.json-based pinning (use Volta) or multi-language version management (use mise).
Use Cases
- • Replace nvm with a faster, cross-platform alternative that reads existing .nvmrc files without migration
- • Manage Node.js versions in CI/CD pipelines where speed matters — fnm installs Node in <1 second vs nvm's 5-10 seconds
- • Set up Windows developer environments that need .nvmrc compatibility without nvm's Windows quirks
- • Auto-switch Node.js versions per directory using shell hooks that read .nvmrc or .node-version files
- • Install multiple Node.js versions in parallel for testing compatibility across LTS releases
Not For
- • Non-Node.js runtime management — fnm is Node.js only; use mise or asdf for polyglot version management
- • Teams that need per-project pinning without shell hooks — Volta's package.json integration is more reliable for team consistency
- • Environments without shell hook support — fnm requires eval in shell rc file for auto-switching
Interface
Authentication
No authentication — local CLI tool. Downloads Node.js binaries from official distribution servers.
Pricing
GPL-3.0 licensed. Completely free and open source.
Agent Metadata
Known Gotchas
- ⚠ Requires eval '$(fnm env)' in shell rc file for auto-switching — agents in non-interactive shells won't get automatic version switching
- ⚠ fnm use without --version in a directory without .nvmrc silently uses the default version — verify active version before running Node commands
- ⚠ Windows PowerShell and CMD require different eval syntax than bash/zsh — cross-platform CI scripts need conditional shell setup
- ⚠ fnm stores installations in ~/.local/share/fnm/ on Linux (different paths per OS) — path assumptions break cross-platform scripts
- ⚠ Auto-switching requires --use-on-cd flag in shell hook — not enabled by default, must be explicitly set
- ⚠ fnm list-remote requires network access — offline environments need versions pre-installed before use
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for fnm (Fast Node Manager).
Scores are editorial opinions as of 2026-03-06.