In light of recent events: Threema and the address book

The question whether Threema can be used without access to the address book has been coming up a lot lately. The answer is “Yes”, of course.


According to Germany’s Right to Informational Self-Determination (“Recht auf informationelle Selbstbestimmung”), it is up to each individual to decide about the use and the disclosure of their personal data. Thus, if a messenger requires access to the address book, a potential user is confronted with two choices:

  • to ask all address-book contacts for permission to share their contact details with the messenger operator
  • to not use the messenger

Threema: No access to contact details required

Unlike ordinary messengers, Threema doesn’t use the phone number to uniquely identify users. Instead, the Threema ID serves this purpose. The Threema ID is a randomly generated string; no conclusions about the user’s identity can be drawn from it. And since linking a phone number or email address to a Threema ID is optional, Threema can be used completely anonymously.

In Threema, users enable or disable contact synchronization at their own discretion. (Detailed information about contact synchronization can be found here.) It’s not necessary to grant Threema access to the address book. If no access is granted, contacts can be added manually by entering their Threema IDs or by scanning the respective QR codes.

As far as chat apps are concerned, there is a lot more to privacy protection than mere message encryption. Find out how common messengers hold up against Threema’s strict privacy standards in this comparison.

Threema 50% off for three days

In the Google Play Store, Threema is currently showcased as “special offer”, and the app is on sale for a short time.

We are happy about the promotion; however, we don’t want to neglect the other platforms. Therefore, we extend the discount to the Threema apps for iOS and Windows Phone.

Until Friday evening, May 26 (CEST), Threema is available at half price for all platforms.

Download Threema now or gift the app
Tell your friends via email

Profile pictures the Threema way

Threema introduces support for profile pictures. You can now add a personal touch to your appearance in Threema without compromising privacy.

The new feature allows you to set a picture that represents you in your chat partners’ contact lists. Setting a profile picture as well as displaying the ones your contacts have set is optional, of course. And if you set a profile picture, you can choose whether it will be sent to selected contacts only or to everyone with whom you chat.

Threema users have full control over who can and who cannot see their profile picture. To ensure privacy, profile pictures are not stored on a server, they are transmitted between users upon message exchange. Like any other content, profile pictures are end-to-end encrypted.

Update to the latest Threema version for Android, iOS, or Windows Phone to enjoy privacy-friendly profile pictures. Details about the individual app releases can be found in the change log.

Threema for Windows Phone gets a host of new features

Threema 1.8.0 for Windows Phone is available for download. This update introduces quite a few new features:

  • Unsent messages are saved as drafts
  • Messages can be deleted in bulk by using the new selection tool
  • Contacts can be blocked individually (by enabling “Block contact” in a contact’s detail view)
  • Streamlined backup and restore process; the Threema ID is now included in data backups
  • The status of a chat’s latest message is now indicated in the chat overview
  • A new setting (in Settings > Privacy) allows to specify whether contacts are sorted by first or by last name

Furthermore, the 1.8.0 update also includes some bug fixes and miscellaneous other improvements.

Threema Gateway: some real-world use cases

With Threema Gateway, Threema can be integrated into existing software applications. This allows companies and organizations to send, receive, and process Threema messages using their own software. Threema Gateway can be used for various purposes – the possibilities are virtually endless. Here are some real-world examples:

  • IncaMail, Swiss Post’s secure email service, uses Threema Gateway to forward encrypted emails. For example, payslips can be received not only as secure email but also as Threema message.
  • With a plugin, Threema can be used for two-factor authentication in the forum software xenForo.
  • Mercedes-Benz uses Threema Gateway for their messenger newsletter.
  • Whappodo, which now also supports Threema, is a solution for customer care and broadcasting via instant messenger.
  • AMBER Alert Germany notifies the people via Threema about cases of missing children.

Besides the above-mentioned xenForo plugin, there are many other Open Source projects that use Threema Gateway, e.g., Grafana and Mattermost.

To learn more, please visit the Threema Gateway website.

Threema for iOS: Message previews and interactive notifications

With Threema 2.9.0 for iOS, message previews can be displayed in push notifications. This feature requires iOS 10 or later and can be enabled/disabled in Settings > Notifications > Push Notifications. When receiving a push notification, Threema first downloads the corresponding message from the Threema server and decrypts it in the background in order to display a preview of the message content. To learn more about the security implications of enabling this setting, please refer to this FAQ article.

If message preview is enabled, push notifications are interactive, allowing you to reply to (or agree/disagree with) a message right from the push notification – even on the Apple Watch.

Besides other improvements, the 2.9.0 update also provides a handy date/time picker for easy scheduling of appointments in polls. Visit the changelog.

Daimler uses Threema Work as company messenger

A few months ago, Threema Work was successfully launched. Threema Work is tailored to the internal communication needs of companies and organizations. With Threema Work’s unique management cockpit, even large organizations can keep full control over the use of the app.

We are delighted that Daimler AG has chosen Threema Work as internal messaging tool. Daimler AG is in good company. Many well-known corporations have already started using Threema Work. Numerous small and medium-sized businesses as well as public institutions have also opted for Threema Work.

Learn more about Threema Work now.

Threema Work: Windows Phone version and support for Threema Web

Threema Work, the secure and privacy-compliant messaging solution for organizations, is now available for Windows Phone. Thus, Threema Work can now be used on all major mobile platforms.

Threema Work 3.11k for Android introduces support for Threema Web (as well as a new image editor). Messages and files can now be sent and received conveniently on the desktop. At this time, Threema Web is available for the Android version of the Threema Work app; support for other platforms is in preparation. Find out more.

Threema Web: Connectivity and performance improvements

Threema Web has already gained high popularity. With the help of the Threema community on GitHub, it has also received numerous updates already. The most important improvements at a glance:

  • Increased compatibility with corporate firewalls
  • Reduced battery consumption of the mobile device
  • Images can now also be sent using “copy and paste”
  • Improved performance of Threema Web in the browser

Technically inclined users might want to have a look at Threema Web’s change log on GitHub.

Get creative with Threema for Android’s new image editor

Threema 3.1 for Android introduces new image editing options. You can now spice up your images by drawing on them, adding text, and inserting stickers – without leaving the Threema app.

First, select the image you would like to send. In the preview, tap the paintbrush icon in the title bar to open the image editor. Draw whatever you like, add text, and insert, move, resize and rotate stickers. Tap and hold any item to flip it horizontally, bring it to the front, or delete it. Of course, you can also adjust the color of the brushstrokes and the text.

As always, the update includes some bug fixes and general improvements. Visit the change log.

Threema 2.8.1 for iOS: Message drafts and more

A new Threema version for iOS has just hit the App Store. The 2.8.1 update for iOS introduces message drafts: If you compose a message without sending it, the message will be saved as draft, and it is indicated in the chat list that there’s an unsent message in that conversation. Furthermore, it’s now apparent at a glance which messages are new in a chat thanks to a divider bar.

This update also includes some other additions and improvements. To learn more, please consult the change log.

Threema Web. Threema’s web client is here

Threema arrives on the desktop. Threema Web allows to conveniently chat from the computer without compromising security. The handling is intuitive, and the user has full access to all chats, contacts, and media files.

Highest security and data restraint

As to be expected, Threema’s way of implementing a web client ensures both highest security and maximum data restraint. Instead of using a server for message synchronization, Threema Web establishes an encrypted direct connection between browser and mobile device. This way, messages can be synchronized without having to pass a server. If browser and mobile device are connected to the same network, the data packets never leave the network. In contrast to common, server-based approaches, Threema Web significantly reduces the digital footprint and limits the generation of metadata to the bare minimum. After a session has ended, the synchronized messages are deleted immediately on the desktop. Threema Web acts as an extension of the Threema app and meets the high security standard set by the Threema app.

Complete message synchronization

The sole requirement to use Threema Web is a current web browser (Chromium, Google Chrome, Mozilla Firefox, or Opera). By scanning a QR code, browser and mobile device are connected at once. All chats are fully available on the desktop, and the devices are synchronized seamlessly. UI-wise, Threema Web is modeled after the Threema app. Messages are sent and received just like on the mobile device; images and files can be conveniently sent using drag and drop.

Open source

Threema Web is open source; the source code is available on GitHub, and even self-hosting is possible. To handle the direct communication between browser and mobile device, SaltyRTC is used. SaltyRTC adds an additional encryption layer to the open standard WebRTC and ensures a secure connection between browser and mobile device. Signaling is also carried out by SaltyRTC using strong encryption. The SaltyRTC protocol was developed specifically for Threema Web and is based on the tried and trusted NaCl cryptography library, which is highly regarded by experts.

Additional information:

Threema 1.7.0 for Windows Phone

A new Threema version for Windows Phone is ready for download. These are the changes and additions the 1.7.0 update introduces:

  • New design featuring circular contact pictures
  • Support for basic text markup
  • URL actions for adding IDs and composing messages
  • Various other improvements and bug fixes

Learn more about text markup here.
Learn more about URL actions here.

Data Privacy Day – Threema 50% off

January 28 is Data Privacy Day. This holiday was established in order to raise awareness for data protection and to point out the dangers of a decline in privacy. Privacy awareness is more important than ever. In addition to surveillance programs by governments and data breaches, privacy violations by companies undermine the privacy of Internet users.

Users are often unaware of the amount and the kind of data they disclose by using certain online services. There’s also a lack of awareness for the consequences of giving up one’s privacy. Data is power. Once collected, data can be endlessly reproduced and stored until the end of time. What’s more, user data might lead to unforeseen conclusions about the users, especially when collected in large quantities and merged with data from other sources.

Threema was designed to generate as little data as possible in the first place. For where there is no data, no data can be misused.

The Data Privacy Day is a great opportunity to reconsider one’s communication habits. Threema is a valuable tool to ensure security and confidentiality of your communication. On the occasion of this year’s Data Privacy Day, the Threema app is available for half the price on all supported platforms.

The 50% sale ends on Sunday, January 29, at 10 p.m. CET.

Download Threema here

Spread the word: email template

Threema arrives on the Desktop (beta)

Today, Threema’s web client enters the closed beta stage (limited to existing testers), and it will soon be available to all Android users. Support for other platforms will follow at a later date.

Threema Web connects browser and app via the shortest path using SaltyRTC. Our technical approach provides highest security and maximum data restraint. More detailed information will be available soon.

The public release of Threema Web is scheduled for early 2017. We will let you know as soon as the beta phase has been completed. Stay tuned!