Install Nix on Linux: single-user and multi-user mode

Installing Nix takes less than 5 minutes and puts most of its files in the /nix directory. You can install it on Debian, Ubuntu, Fedora, Arch or any Linux distribution, and uninstall it cleanly if needed. This guide covers the two installation modes, the initial setup of the modern commands and flakes, and a first test to check that everything works. The outputs shown were captured on Nix 2.35.2.

What you will learn

• Choose between the single-user and multi-user installation for your context
• Install Nix on your Linux distribution with an installer checked against its hash
• Enable the modern commands (nix shell, nix profile, nix search) and flakes
• Check that the installation works with a first temporary package
• Uninstall Nix cleanly if needed

In what context?

You have read the guide on the Nix ecosystem and want to get hands-on. Here are the typical situations:

• You run a Debian or Ubuntu server and want to try Nix without touching your existing apt installation.
• You work on several projects that need different versions of Python, Node.js or Terraform.
• You are preparing a reproducible environment for your team.
• You are on a shared workstation and need to isolate your packages.

Prerequisites

• A Linux system with root access (sudo)
• curl installed (present by default on most distributions)
• At least 5 GB of free disk space for /nix
• An Internet connection

# Check that curl is available
which curl || sudo apt install curl  # Debian/Ubuntu

Choose between single-user and multi-user

Nix offers two installation modes, and the choice depends on your usage. The deciding criterion is privilege separation: in multi-user mode, a daemon builds packages under dedicated accounts, which protects the store from the other users of the machine.

Criterion	Single-user	Multi-user
Daemon	No	Yes (nix-daemon)
Isolation	No privilege separation	Builds isolated in dedicated accounts
Users	Only one	Several
Recommended for	Quick tests, personal workstation	Servers, shared workstations, production
Rights needed to install	Current user	Root (for the daemon)

Swipe to see more

Which mode to choose?

When in doubt, choose multi-user. It is the mode recommended by the Nix manual whenever the platform supports it and you have sudo. It is safer (builds run in dedicated nixbld* accounts) and it is the one used in all the guides of this section.

Download and check the installer

The nixos.org download page suggests piping the installation script into sh. Do not: you would run as root a script nobody has read, without knowing which version it installs. For each version, the project publishes the script and its SHA-256 hash on releases.nixos.org: download both, compare, read the script, and only then run it.

curl -fsSL -o install-nix.sh https://releases.nixos.org/nix/nix-2.35.2/install
curl -fsSL https://releases.nixos.org/nix/nix-2.35.2/install.sha256
sha256sum install-nix.sh
less install-nix.sh

The two hashes must match, measured on 1 October 2026: 9adda97297d9e8ab360df95c729eabff4f4f93d6db091953c3a68f29e3fb130c. The script in turn pins the Nix 2.35.2 archive of each architecture by its hash, and refuses an archive that does not match it.

Install Nix in single-user mode

Single-user mode is the simplest. Nix installs into /nix and runs directly under your user, without a daemon. Run the checked script with the --no-daemon option:

sh install-nix.sh --no-daemon

1. The installer downloads Nix and creates the /nix/store/ directory
2. It configures your shell by adding a loading line to ~/.profile
3. The Nix commands become available in your PATH

New terminal required

After installation, open a new terminal so that the PATH is updated. Otherwise, load the profile script by hand:

. ~/.nix-profile/etc/profile.d/nix.sh

Install Nix in multi-user mode

Multi-user mode creates a system daemon (nix-daemon) and a group of dedicated accounts (nixbld1 to nixbld32) to isolate builds. Unlike single-user mode, it also touches a few system files outside /nix, which uninstalling will have to remove.

sh install-nix.sh --daemon

The installer asks a few questions. Answer yes each time to accept the defaults.

1. The installer creates the /nix/store/ directory and the build accounts nixbld*
2. It installs and starts the service nix-daemon.service, and writes /etc/nix/nix.conf
3. It creates /etc/profile.d/nix.sh and adds a loading line to the global shell files (/etc/bash.bashrc or /etc/bashrc, /etc/zshrc), so that every user has Nix in their PATH

After installation, check that the daemon is running:

systemctl status nix-daemon.service

Expected output:

● nix-daemon.service - Nix Daemon
     Loaded: loaded (/etc/systemd/system/nix-daemon.service; linked; preset: enabled)
     Active: active (running)
   Main PID: 2383 (nix-daemon)

Alternative: the Determinate Nix Installer

The Determinate Nix Installer, maintained by the company Determinate Systems, is an alternative to the official installer. It always installs in multi-user mode, enables flakes by default, and provides a one-command uninstall (/nix/nix-installer uninstall). Its documentation, too, suggests piping a script into sh: the same rule applies, you download, read, then run.

Official installer vs Determinate

Mind what you actually install: by default, this installer deploys Determinate Nix, the Nix distribution published by Determinate Systems, and not the upstream Nix of the NixOS project. The option that installs upstream Nix (--prefer-upstream-nix) is described by its README as unsupported and likely to disappear. This guide, like the rest of the section, uses the official installer.

Check the installation

Open a new terminal (or source the profile by hand) and test:

nix --version

nix (Nix) 2.35.2

Also check that the store is reachable through the daemon:

nix store info

Store URL: daemon
Version: 2.35.2
Trusted: 0

Store URL: daemon confirms that your command does go through the daemon. The Trusted line tells whether your account is listed in trusted-users, which is root by default: an ordinary user therefore reads Trusted: 0, and that is normal. Only root (or an account added to trusted-users) reads Trusted: 1, which allows sensitive settings such as adding a binary cache.

Enable the modern commands and flakes

By default, the modern commands (nix shell, nix profile, nix search, nix develop) and flakes are disabled, because the Nix team still considers them experimental, even though the community uses them heavily. On Nix 2.35.2, the slightest of these commands fails until the feature is enabled:

error: experimental Nix feature 'nix-command' is disabled; add '--extra-experimental-features nix-command' to enable it

Add the line to the /etc/nix/nix.conf file, after what the installer wrote there (tee -a appends without overwriting):

echo "experimental-features = nix-command flakes" | sudo tee -a /etc/nix/nix.conf

Then restart the daemon:

sudo systemctl restart nix-daemon.service

Check that the configuration is taken into account:

nix config show experimental-features

fetch-tree flakes nix-command

fetch-tree appears on its own: it is a feature that flakes depend on, enabled automatically along with them. There is no need, on the other hand, to write sandbox = true: the build sandbox is already active by default on Linux.

What are these features?

• nix-command enables the unified CLI (nix shell, nix profile, nix search, nix build...) that replaces the old separate commands (nix-env, nix-shell, nix-build).
• flakes enables the dependency system with a lock file that guarantees reproducibility (flake.nix + flake.lock).

Configure your shell

Bash and Zsh

In multi-user mode, the installer adds the Nix loading line to the global shell files, read when a session opens. If the Nix commands are not available after logging in, add the loading of the daemon script to your ~/.bashrc or ~/.zshrc:

# Load Nix
if [ -e /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh ]; then
  . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
fi

Fish

For Fish, add to ~/.config/fish/config.fish the script that matches your installation mode: nix-daemon.fish in multi-user mode, nix.fish in single-user mode.

# Load Nix (multi-user installation)
if test -e /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.fish
  source /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.fish
end

Test with a first temporary package

Let us check that Nix works end to end by running a package without installing it:

nix run nixpkgs#cowsay -- 'Nix works!'

The first run downloads the dependencies from the binary cache:

 ____________
< Nix works! >
 ------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

The cowsay package is not installed in your profile. It was downloaded into the store (/nix/store/) and run only once. You can check it:

which cowsay
# cowsay not found: it is not in your PATH

This is one of the strengths of Nix: trying a tool in one command, without polluting your system.

Uninstall Nix cleanly

If you want to remove Nix from your system, follow the procedure of the Nix manual for your installation mode. The multi-user version has more steps, because the installer touched system files and created accounts.

Multi-user

The four steps follow the order of the manual: stop the daemon, delete the files, remove the build accounts, then clean the global shell files. Skip the last one and every new shell will print an error while looking for a script that no longer exists.

1. Stop the daemon:

   sudo systemctl stop nix-daemon.service
   sudo systemctl disable nix-daemon.socket nix-daemon.service
   sudo systemctl daemon-reload

2. Delete the Nix files, those of your account and those of root:

   sudo rm -rf /etc/nix /etc/profile.d/nix.sh /etc/tmpfiles.d/nix-daemon.conf /nix \
     ~root/.nix-channels ~root/.nix-defexpr ~root/.nix-profile ~root/.cache/nix
   rm -rf ~/.nix-profile ~/.nix-defexpr ~/.nix-channels \
     ~/.local/share/nix ~/.local/state/nix ~/.cache/nix

3. Delete the accounts and the group:

   for i in $(seq 1 32); do sudo userdel "nixbld$i"; done
   sudo groupdel nixbld

4. Remove the lines added by the installer to /etc/bash.bashrc, /etc/bashrc, /etc/profile, /etc/zsh/zshrc and /etc/zshrc, depending on which ones exist on your distribution.

Single-user

rm -rf /nix ~/.nix-channels ~/.nix-defexpr ~/.nix-profile \
  ~/.local/share/nix ~/.local/state/nix ~/.cache/nix

Also remove the loading line added to ~/.profile.

Troubleshooting

Most blockers come down to a shell that has not loaded Nix yet, a stopped daemon, or experimental features that are not enabled. Read the exact message: the one in the fourth row names the missing option itself.

Symptom	Likely cause	Solution
nix: command not found after installation	Shell not reloaded	Open a new terminal or source the profile by hand
error: getting status of /nix	/nix does not exist	Run the installer again
error: cannot connect to daemon	nix-daemon stopped	sudo systemctl start nix-daemon.service
error: experimental Nix feature 'nix-command' is disabled	Modern commands not enabled	Add experimental-features = nix-command flakes to /etc/nix/nix.conf
permission denied on /nix/store/	Single-user installation with the wrong owner	Check ls -ld /nix/store, the owner must be your user (single) or root (multi)

Swipe to see more

Key points

• Multi-user mode is recommended: it isolates builds in dedicated accounts and works for every user of the system.
• Enable nix-command and flakes in /etc/nix/nix.conf, it is essential to follow the guides of this section.
• Nix leaves your packages alone: apt, dnf and what they installed stay intact, Nix packages live in /nix.
• Test with nix run nixpkgs#cowsay to check that everything works end to end.
• Uninstalling a multi-user setup takes four steps: daemon, files, nixbld* accounts, then global shell files.

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