Threema started as an abbreviation: “EEEMA,” for “End-to-End Encrypted Messaging Application.” The three “E”s were a bit unwieldy, so it became “Threema.”
Threema is the world’s best-selling secure messenger. It sets itself apart from others in the following respects:
- Privacy as a guiding principle: Threema is designed to generate as little data on servers as
- Full anonymity: You are not forced to provide any personal information
(such as your phone number or email address) in order to use Threema.
- Open source: To provide full transparency, the Threema apps are open source.
Anyone knowledgeable enough can confirm Threema’s security on their own.
- Optional contact synchronization: It’s not necessary to grant access to the address book in order to use Threema.
- Comprehensive encryption: In Threema, all your communication is end-to-end encrypted – not just text messages and voice and video calls but also group chats, media files, and even status
- Rich functionality: Threema is versatile and feature-rich.
In contrast to other messengers, your identity in Threema does not depend on a phone number. Each Threema user gets a randomly generated, 8-digit Threema ID when starting the app for the first time. This ID is your unique address in Threema and makes it possible to use Threema completely anonymously, without disclosing any personal information.
Your Threema ID is just one of two components that make up your identity in Threema. The other one is the so-called key pair (consisting of a public key and a private key) which is essential for the encryption. Your Threema ID is permanently tied to your public key. While the public key is sent to Threema’s servers to be distributed to your chat partners, the private key remains on your device where it is securely stored. All messages directed to you will be individually encrypted with your public key on the sender’s device. They can only be decrypted with your personal private key.
|Wearables* (e.g., Smartwatch)||Apple Watch*|
|Android Auto||Apple CarPlay|
Threema is fully supported.
Threema is not supported.
* If you are using Threema with an Android Wear smartwatch or an Apple Watch, you can read message previews, see chat pictures, agree/disagree to incoming messages, and answer messages using dictation (or using Scribble on an Apple Watch).
Threema is currently available in the following languages:
- Basque (Spain) (iOS)
- Brazilian Portuguese
- Catalan (Android)
- Chinese (traditional and simplified)
- Norwegian (Bokmål)
If Threema doesn’t support the device’s system language, the user’s preferred languages (as defined in the system settings) will be taken into account. If these languages aren’t available in Threema, English serves as fallback.
Is Threema not yet available in your language? Support the translation here:
Yes. Both servers and offices only use energy from renewable sources.
The development of the Threema apps and the maintenance of the server infrastructure generates costs. The app price covers these costs.
If we wanted to offer our apps for free, we would have to monetize user data, which, of course, would totally undermine Threema’s purpose (i.e., to protect the users’ data and privacy). Besides, Threema is designed from the ground up to only generate as little user data as technically possible, so there’s next to no user data to begin with.
First of all, if you have recently used your Threema ID on another device (i.e., if you have switched devices or if you have turned on a device that has been lying in storage), you can ignore this warning. To prevent it from (re)occurring when changing devices, it’s recommended to uninstall Threema on the previous device and then restart the current one.
If, however, you are certain that you’re not using your Threema ID on any other device, then your private key may be compromised. You should revoke your Threema ID and follow the steps listed below before creating a new ID.
- Ensure your device’s software is up to date
- If system updates are no longer available for your device, consider replacing the device with a current model
- Check your device for malware; when in doubt, reset the device
- Avoid “rooting” or “jailbreaking” your device
- Change passwords of important user accounts
- Lock your device and the Threema app with a passcode
- Don’t use easy-to-guess passwords (especially for Threema Safe), and never reuse the same password for different purposes. Use a password manager.
- Delete and reinstall the Threema app from an official source before creating a new ID. Please note that you will lose all Threema data (chat history, contact list, etc.), which is why you should export this data (in case you still need it) before reinstalling the app.