DietPi’s lean footprint and Debian underpinnings make it ideal for small SBCs (Raspberry Pi, Odroid, Rock64) and low-powered home servers. It uses APT as its package manager, enhanced by the dietpi-software installer for one-click deployments. Most installs are headless or use lightweight desktops like LXDE/Openbox, so any VPN should be command-line friendly, low on dependencies and integrate cleanly with systemd. Below are the VPNs best suited to this environment, along with step-by-step guides for the top three.

Why These VPNs Are Ideal for DietPi

• WireGuard – Part of the Linux kernel, minimal userland tools, super-light on CPU/memory and packaged in Debian bullseye/backports.
• Mullvad – Offers an APT repository, a simple CLI client and strong privacy, all in a small footprint.
• ProtonVPN – Official Debian repo, CLI app, systemd integration, works headless.
• OpenVPN – Universal, but heavier and requires more manual config still available via APT.
• NordVPN – Provides a .deb and CLI tool, but is slightly bulkier compared to the others.

Comparison Table

1. WireGuard Installation Configuration

Installation

WireGuard is included in Debian’s repositories. On DietPi, you can install via APT or use the built-in installer:

apt update
apt install wireguard

Configuration

Create keys and a basic interface file at /etc/wireguard/wg0.conf:

wg genkey  tee /etc/wireguard/privatekey  wg pubkey > /etc/wireguard/publickey

cat gt /etc/wireguard/wg0.conf ltltEOF
[Interface]
Address = 10.0.0.2/24
PrivateKey = (cat /etc/wireguard/privatekey)
ListenPort = 51820

[Peer]
PublicKey = YOUR_PEER_PUBLIC_KEY
Endpoint = vpn.example.com:51820
AllowedIPs = 0.0.0.0/0
PersistentKeepalive = 25
EOF

chmod 600 /etc/wireguard/privatekey
systemctl enable wg-quick@wg0
systemctl start wg-quick@wg0

Adjust AllowedIPs or Endpoint as required. Check status with wg.

2. Mullvad VPN Installation Configuration

Installation

Mullvad provides its own repository and keyring:

apt update
# Import Mullvad’s signing key
wget -O- https://mullvad.net/media/app/deb/etc/apt/trusted.gpg.d/mullvad-vpn-archive-keyring.gpg 
   gpg --dearmor  tee /usr/share/keyrings/mullvad-vpn-archive-keyring.gpg
# Add repository
echo deb [signed-by=/usr/share/keyrings/mullvad-vpn-archive-keyring.gpg] 
https://deb.mullvad.net/apt stable main 
   tee /etc/apt/sources.list.d/mullvad-vpn.list
apt update
apt install mullvad-vpn

Configuration Usage

# Check status
mullvad status

# Log in (enter your Mullvad account number)
mullvad login

# Connect to the fastest server
mullvad connect

# Disconnect when done
mullvad disconnect

3. ProtonVPN Installation Configuration

Installation

apt update
apt install -y wget gnupg
# Add ProtonVPN GPG key
wget -qO - https://repo.protonvpn.com/debian/public_key.asc  apt-key add -
# Add repository
echo deb https://repo.protonvpn.com/debian stable main 
   tee /etc/apt/sources.list.d/protonvpn.list
apt update
apt install protonvpn-cli

Configuration Usage

# Log in with your ProtonVPN credentials
protonvpn-cli login

# Connect to the fastest server automatically
protonvpn-cli c --fastest

# To disconnect
protonvpn-cli d

Each of these VPNs integrates smoothly on DietPi’s minimal system. WireGuard offers unmatched speed and simplicity, Mullvad combines straightforward CLI controls with strong privacy, and ProtonVPN brings an official Debian-backed client. Choose based on your specific needs—whether pure openness, privacy ethos or official vendor support.