Description
Threema is a Swiss end-to-end encrypted messenger that can be used without a phone number or e-mail address, for a one-time price, with open-source apps and servers in Switzerland.
The app has been developed in Switzerland since 2012, and Threema GmbH was founded in 2014. The private app costs a one-time 6.00 (CHF, EUR or USD, depending on the store), with no ads and no subscription; each user gets a random Threema ID instead of a phone number. The apps are open source under the AGPLv3 licence, with reproducible builds on Android still described as experimental, and a Google-free Android version, Threema Libre, has been on F-Droid since 2022. Threema runs its own servers at separate sites in Switzerland, including an ISO 27001 data centre in Zurich. Security audits include the Münster Lab for IT Security (2019), Cure53 for the mobile apps (2020) and the desktop app (2024), and a formal proof of its Ibex protocol (2023).
It had more than 10 million users in 2021. Threema Work, for companies, costs from 3 per user a month. After the investor Afinum held it from 2020, the Frankfurt private equity firm Comitis Capital bought Threema from Afinum and the founders in January 2026; the price was not disclosed.
Strengths
- No phone number or e-mail is needed, so the address book isn’t uploaded and accounts can’t be linked to a SIM.
- The apps are open source and have been audited several times, and the servers are in Switzerland.
- A single payment covers the app, with no ads, no subscription and no data sold.
Weaknesses
- It has been sold to private equity twice, most recently to Comitis Capital in January 2026, and the founders have left.
- Contacts have to install and pay for Threema too, which makes moving a family or club harder than with free apps.
- Reproducible builds, which let anyone check that the app matches the published code, exist only on Android and are still experimental.
Who it is for
People who want a messenger without a phone number or e-mail, with servers in Switzerland, and who can convince their contacts to pay a few francs for the app.