SimpleX Chat

SimpleX goes further than anything else here on hiding who you talk to. Where Signal ties you to a phone number and most rivals hand you a random user ID, SimpleX assigns no identifier at all, not even an internal one. The servers relaying your messages have no way to work out who is talking to whom. It’s open source under the AGPL and uses quantum-resistant end-to-end encryption. You can even run your own servers while still reaching people on the public ones. Adding someone means sharing a one-time link or QR code instead of a username. The network is younger and smaller than Signal so you will be inviting people rather than finding them. On pure metadata privacy nothing else comes close.