fnm install Command Guide

The fnm install command is used to install new Node.js versions.

Command Syntax

fnm install [OPTIONS] [VERSION]

Parameters

VERSION

Specify the Node.js version to install:

# Install major version (automatically selects latest minor version)
fnm install 20

# Install specific version
fnm install 20.10.0

# Install LTS version
fnm install lts/iron

# No version specified, reads from version file
fnm install

Options

--lts

Install the latest LTS (Long Term Support) version:

fnm install --lts

--latest

Install the latest version (including non-LTS):

fnm install --latest

--use

Switch to the version immediately after installation:

fnm install 20 --use

--progress

Control download progress bar display:

# Auto display (default)
fnm install 20 --progress=auto

# Always display
fnm install 20 --progress=always

# Never display
fnm install 20 --progress=never

--node-dist-mirror

Specify Node.js download mirror:

fnm install 20 --node-dist-mirror=https://npmmirror.com/mirrors/node

--arch

Specify the installation architecture:

# Install x64 version
fnm install 20 --arch=x64

# Install ARM64 version
fnm install 20 --arch=arm64

--fnm-dir

Specify fnm installation directory:

fnm install 20 --fnm-dir=/custom/path

--log-level

Set log level:

fnm install 20 --log-level=quiet
fnm install 20 --log-level=error
fnm install 20 --log-level=info

--corepack-enabled

Enable Corepack support:

fnm install 20 --corepack-enabled

Usage Examples

Install LTS Version

# Install latest LTS
fnm install --lts

# Install specific LTS version
fnm install lts/iron    # Node.js 20.x
fnm install lts/hydrogen # Node.js 18.x

Install Specific Version

# Install major version
fnm install 20

# Install minor version
fnm install 20.10

# Install exact version
fnm install 20.10.0

Install and Use

# Install and switch immediately
fnm install 20 --use

# Install and set as default
fnm install 20 --use && fnm default 20

Use Mirror for Faster Download

# Use mirror
fnm install 20 --node-dist-mirror=https://npmmirror.com/mirrors/node

Install Specific Architecture

# Install x64 version on Apple Silicon Mac
fnm install 20 --arch=x64

Version Formats

fnm supports multiple version formats:

Format	Example	Description
Major version	20	Latest 20.x.x
Minor version	20.10	Latest 20.10.x
Exact version	20.10.0	Exact version
LTS name	lts/iron	LTS version codename
latest	--latest	Latest version

LTS Version Codenames

Codename	Version	Release Date
Iron	20.x	2023-10
Hydrogen	18.x	2022-10
Gallium	16.x	2021-10
Erbium	14.x	2020-10
Dubnium	12.x	2019-10

Environment Variables

You can configure default behavior through environment variables:

# Set mirror
export FNM_NODE_DIST_MIRROR=https://npmmirror.com/mirrors/node

# Enable Corepack
export FNM_COREPACK_ENABLED=true

# Set installation directory
export FNM_DIR=~/.fnm

Common Issues

Installation Failed

# Try using mirror
fnm install 20 --node-dist-mirror=https://npmmirror.com/mirrors/node

# View detailed logs
fnm install 20 --log-level=info

Version Already Exists

# View installed versions
fnm list

# Use installed version
fnm use 20

Slow Download

# Configure mirror
export FNM_NODE_DIST_MIRROR=https://npmmirror.com/mirrors/node
fnm install 20

Related Links

• Install Node.js - Installation guide
• Command Reference - All command details
• Download Management - Download configuration