Welcome.

Secure end-to-end encrypted messaging - from your Desktop or Laptop.

What this is

OpenMittsu is a cross-platform open source implementation and desktop client for the Threema Messenger App.

Supported Platforms

Currently we support

Windows 7, 8, 8.1 and 10, both in 32bit and 64bit,
Debian 9, 10 and 11 in 32bit and 64bit on amd64/i386 as well as PPC,
many, if not all, Linux flavors,
Mac OS X.

Features

Feature	Groups	Single Contact
Text	Send/Receive	Send/Receive
Images	Send/Receive	Send/Receive
Locations	Receive	Receive
Files	Send/Receive	Send/Receive
Audio	Receive	Receive
Videos	Receive	Receive
Calls	Not supported	Not supported
Polls	Not supported	Not supported

ToDo

better UI (HTML5 driven chat windows)
Wizards for initial configuration
Support for Threema calls and file messages
and so much more...

Interested?

We are always looking for contributors! Take a look at the source.