Delta Chat is a free instant messaging app for mobile and desktop, with versions for Android, iOS, Linux, macOS, and Windows, as well as self-hosting. It relays messages through chatmail relays and supports multiple profiles and devices. Messages, attachments, and attachment metadata are end-to-end encrypted by default using a subset of OpenPGP with Secure-Join and Autocrypt. Servers can still see sender and recipient addresses and message size; other message, contact, and group metadata is encrypted. Chats can contain interactive web apps for gaming and collaboration. Audio and video calls on Android and iOS use peer-to-peer WebRTC, but a March 2026 post said the feature remained behind a debug setting. A classic email address can serve as a relay only if chatmail clients use it exclusively, and classic email providers generally lack push notifications. The FAQ says there are no immediate plans for a web client. Delta Chat links to a forum for support and feedback.
Who it is for
Delta Chat suits people looking for an encrypted messaging app across mobile and desktop platforms, including those who want multiple profiles or devices. Its relay and web-client limitations matter for people relying on classic email or browser access.
What is good
- Messages and attachments are encrypted by default.
- Available across mobile and desktop platforms.
- Chats support interactive web apps.
- Free plan; no trial required.
What to know first
- Servers can see addresses and message size.
- No immediate plans for a web client.
- Calls remained behind a debug setting in March 2026.
- Classic email relays have limited support and no typical push.
Verdict
Delta Chat offers default end-to-end encryption and broad platform support at no charge. Note the visible server metadata and the stated limitations around browser access, classic email, and calls.
Delta Chat plans and pricing
All plansCompared on secure messaging apps
- Free plan
- Yes
- Encryption coverage
- default
- Desktop app
- Yes
- Voice and video calls
- Yes
- Disappearing messages
- Yes
- Encrypted backups
- none
