Messenger
Threema and data protection
Threema is developed by Threema GmbH in Pfäffikon SZ; its servers are located in Switzerland. The app costs a small one-off fee. In return, the service is not financed through advertising or data.
In brief
- Usable without a phone number: you get a random Threema ID. You can choose to link a phone number or email address.
- Everything end-to-end encrypted: one-to-one and group chats, calls and files.
- Data-minimising: messages are deleted from the server once delivered; contact lists are only matched in encrypted form.
- Open source: the source code of the apps is public and is regularly audited externally.
- Swiss law: Threema is subject to the Swiss Federal Act on Data Protection (FADP).
What you should bear in mind
- Fewer people use Threema than WhatsApp. You may first have to persuade your contacts.
- If you lose your device and have no backup, your Threema ID is lost too.
- There is a separate version for businesses (Threema Work).
How to set up Threema in a privacy-friendly way
The labels may differ slightly depending on the app version.
- Create an ID backup: My profile → export Threema ID or data backup. Keep the password in a safe place.
- Set a revocation password: My profile → ID revocation password. This lets you delete the ID permanently later on.
- Only link your phone number if you need to: without linking, you can find your contacts via QR code or ID.
- Reconsider contact sync: Settings → Privacy → only turn on “Sync contacts” if you want your contacts to be found automatically.
- Verify contacts: when you meet in person, scan your contacts’ QR code (three dots = verified).
- Turn on the app lock: Settings → Security → Locking mechanism.
Further reading
Sources
- Threema: Website and security information
- Threema: Open source