Threema is a secure messaging app designed for privacy. It was developed and operated entirely in Switzerland.
Threema does not require a phone number or email address for registration. Instead, users are assigned a unique Threema ID, enabling confidential communication without revealing personal information.
The app’s zero-knowledge architecture means that only the intended recipients can read messages—neither Threema nor third parties have access to message content. Threema also minimizes metadata, storing contacts and messages on users’ devices rather than on central servers. Messages are deleted from Threema’s servers immediately after delivery, further reducing digital footprints.
Threema has regular external audits and reproducible builds. The company adheres to strict Swiss data protection laws and is fully GDPR-compliant.
User Experience
Threema is available for iOS and Android, with a desktop client that works via QR code. The app supports group chats, polls, file sharing, and voice or video calls—all with strong encryption. Users can edit or delete sent messages and verify contacts using QR codes to guard against man-in-the-middle attacks.
Threema has a one-time purchase price typically around $6.
