Cwtch vs SimpleX Chat

Cwtch is a free decentralized messaging app for Android, Linux, macOS, and Windows. Direct conversations use Tor v3 onion services to create anonymous peer-to-peer connections between profiles, and Cwtch says communication is end-to-end encrypted over those services. Both participants must be online for peer-to-peer chat. Group conversations and offline delivery use a third-party server designed to learn as little as possible about message contents or metadata. Group messaging is experimental: users must enable the Experiments and Group Experiment settings, and the project calls metadata-resistant group communication an active research area. Conversation history is not preserved between sessions by default, though it can be enabled for an individual conversation. The protocol is open, allowing bots, services, and interfaces to integrate with Cwtch; core library, Go bindings, and interface code are linked as open source. There is no global display-name registry, which the security handbook says increases impersonation risk. The project recommends version 1.17.2, released October 2, 2026, for security fixes. The plan costs nothing.

SimpleX Chat is a messaging application for the SimpleX platform, with apps for Android, iOS, Linux, macOS, and Windows. It supports encrypted text with Markdown and editing, media and file sharing, decentralized groups, voice messages, disappearing messages, and audio and video calls. The network does not assign profile identifiers such as phone numbers or usernames. Messages and metadata use end-to-end encryption with continuous post-quantum key exchange. Four servers participate in each chat so relay servers cannot see which IP addresses communicate. Profiles, contacts, and messages remain in a portable encrypted database on user devices; relay servers hold encrypted messages only until delivery. Users may operate their own servers and still reach people using preconfigured servers. Developers can build bots and integrations using protocol SDKs; the TypeScript SDK connects to the Chat CLI over a WebSocket API. A phone or tablet can link to the desktop app only when both devices share a local network. Disappearing messages and recipient-side deletion are not guaranteed when a recipient device is offline or modified. The free plan costs nothing.