Whonix is a free and open-source desktop operating system (OS) that is specifically designed for advanced security and privacy. Based on Tor, Debian GNU/Linux and the principle of security by isolation, Whonix realistically addresses common attack vectors while maintaining usability.

Online anonymity and censorship circumvention are attainable via fail-safe, automatic, and desktop-wide use of the Tor network, meaning all connections are forced through Tor or blocked. The Tor network helps to protect from traffic analysis by bouncing communications around a distributed network of relays run by global volunteers. Without advanced, end-to-end, NetFlow correlation attacks, an adversary watching an Internet connection cannot easily determine the sites visited, and those sites cannot discover the user's physical location.

Whonix uses an extensively reconfigured Debian base which is run inside multiple virtual machines (VMs) on top of the host OS. This architecture provides a substantial layer of protection from malware and IP leaks. Applications are pre-installed and configured with safe defaults to make them ready for use with minimal user input. The user may install custom applications or personalize their desktop without fear of information leaks that could lead to de-anonymization. Whonix is the only actively developed OS designed to be run inside a VM and paired with Tor. Though technically a "desktop" operating system, the security and anonymity tools Whonix provides also make it ideally suited for hosting secure and anonymous onion services.

Whonix consists of two parts: the Whonix-Gateway and the Whonix-Workstation. The former runs Tor processes and acts as a gateway, while the latter runs user applications on a completely isolated network. The Whonix design affords several benefits: