Threema is the world's best-selling secure communication tool that keeps your data out of the hands of hackers, companies and governments. The service can be used completely anonymously. Threema is open source, allows end-to-end encrypted voice and video calls, and offers all the features one would expect from the latest instant messaging program. With Threema Web, you can also use Threema from your desktop.

Threema was designed from the ground up to generate as little data as possible on the server. Group memberships and contact lists are managed only on your device and are never stored on our servers. Emails are deleted immediately after delivery. Local files are stored on your phone or tablet in an encrypted manner. All this effectively prevents the collection and misuse of your personal information (including metadata). Threema is fully compliant with the European Privacy Regulation (GDPR).

Threema encrypts all your communications end-to-end, including messages, voice and video calls, group chats, files and even status messages. Only the intended recipient, and no one else, can read your messages. Threema uses the trusted open source NaCl encryption library for encryption. Encryption keys are generated and stored securely on the user's device to prevent backdoor access or copying.