Delta Chat vs SimpleX Chat

Delta Chat is a free, open-source messaging app that delivers end-to-end encrypted chats over the existing email network instead of a proprietary server infrastructure. Any two Delta Chat users can message each other using just an email address, with the app handling the IMAP/SMTP plumbing invisibly in the background so it feels like a normal chat app. The project also runs dedicated "chatmail" relay servers for people who want an account without an existing email address, and supports multi-device sync, audited end-to-end encryption, and small in-chat web apps (webxdc) for games and simple tools. Because it rides on open Internet standards rather than a single company's servers, no account can be shut down by one vendor and the core client is developed in the open on GitHub.

SimpleX Chat is an open-source, end-to-end encrypted messenger built around a network design with no persistent user identifiers of any kind, not even random ones. Messages are relayed through servers that see only noise, so there is no phone number, username, or account ID for anyone, including SimpleX, to tie back to a person. The app supports one-to-one and group chats, audio and video calls, file transfer, and multiple chat profiles, and it can run on self-hosted servers for organizations that want full control over their infrastructure. Its protocol and clients are fully open source and have been independently security-audited by Trail of Bits.

• Completely free with no ads, subscriptions, or data monetization.
• Works over infrastructure the user already controls (their own email/chatmail server), avoiding vendor lock-in.
• Open-source codebase lets security researchers audit the encryption implementation.
• No phone number required to create an account, unlike most mainstream messengers.

• No user IDs of any kind, unlike most messengers that rely on phone numbers or usernames
• Fully open-source and independently security-audited
• Self-hostable servers for full infrastructure control
• Free to use across web, desktop, and mobile

• Network effect is small compared to WhatsApp, Telegram, or Signal, so contacts must also install it.
• Email-based transport can feel slower or clunkier than purpose-built messaging protocols for some users.
• Group and multimedia features are less polished than dedicated chat apps with larger engineering teams.

• No central identity means account recovery works differently than typical messengers
• Smaller network effect than mainstream messaging apps
• Some features are more geared toward technical/privacy-focused users