Privacy from whom? If you’re looking for privacy from other users on the platform, Signal and WhatsApp fail miserably because everyone else in the groups you’re

Privacy from whom? If you’re looking for privacy from other users on the platform, Signal and WhatsApp fail miserably because everyone else in the groups you’re in would get your phone number. In Telegram the default is not to expose your phone number to others. If it’s privacy from the platform operators, then Telegram loses because it stores all normal chats in plain text on its servers (though that makes searching a great experience). Signal, to a great extent, and WhatsApp to a lesser extent, try to avoid storing information about your use of the platform. But they do maintain some metadata until the time you delete your account. All the above fail on the phone number requirement to sign up. They’re also centralized platforms depending on the benevolence of one team or company. Matrix is a mix here. It allows you to sign up without revealing your phone number. If you choose to use end-to-end encryption, then all your chats would be encrypted (like in Signal or WhatsApp, where this is the default). But Matrix also stores metadata about you and your presence. My recommendation would be Matrix because you’re not tied to one provider (you can self host it and connect with other Matrix instances, if you wish). The client UI and UX are lacking, but I believe this has a better future on privacy than Signal (with the addition of non-chat features like Mobilecoin).