
Tox is a peer-to-peer instant messaging protocol and set of client apps that connects you with friends and family without anyone else listening in. Unlike centralised services, Tox requires no registration server and no phone number: every client gets a cryptographic identity, and messages are exchanged directly between peers using end-to-end encryption built on open-source libraries.
Tox is free software in both senses of the word: free as in freedom and free as in price. Conversations are encrypted and only the people you talk to can read them, with no company in the middle to mine or sell your data.
Linux, Windows, macOS, Android, iOS (via community clients such as uTox, qTox, Toxic, and aTox).
Open source. GPLv3 (clients vary; the Tox protocol libraries are permissively licensed).