Swiss messenger without phone numbers
Threema GmbH · Communication
Rating
4.3
689 · App Store
Trust
8/9
checks passed · Jul 17, 2026
Platforms
3
iOS, Android, macOS +2
Chart
#3
Communication
Independently checked by Altapp where possible; developer-reported data is labeled as such. Last full review: Jul 17, 2026.
Open-source clients with verifiable Android builds, distributed through official stores and Threema's own shop.
Built for data minimization: no phone number required and no third-party trackers in the app.
Independently audited with a clean recent record; past protocol findings were patched promptly.
Verification reflects the version listed above. Practices may change between releases. How we verify ›
Our verdict: the most metadata-frugal mainstream messenger you can buy — a one-time fee replaces your phone number as the price of admission.
Threema approaches private messaging from a distinctly Swiss angle: pay once, stay anonymous. Instead of a phone number or email address, your identity is a randomly generated eight-digit Threema ID, and the service is designed to generate as little metadata as technically possible. End-to-end encryption covers messages, calls, group chats, files, and status — with the client apps published as open source and, on Android, verifiable through reproducible builds.
The company operates its own servers in Switzerland and finances itself through app sales and its Threema Work business line rather than advertising. Independent scrutiny is part of the routine: Cure53 audited the mobile apps in 2020 and the desktop app in 2024, and when ETH Zurich researchers surfaced protocol weaknesses in 2022, Threema responded with targeted fixes and the new forward-secure Ibex protocol. Desktop apps and a web client round out a mature, quietly maintained ecosystem.
Speak freely, message privately
Choose Signal if
You want a free, independently audited messenger with a much larger user base and don't mind registering with a phone number.
Fast cloud-based messaging at scale
Choose Telegram if
You want huge groups, channels, and seamless multi-device cloud sync more than default end-to-end encryption.
Encrypted email from Switzerland
Choose Proton Mail if
You want Swiss end-to-end encryption for email rather than instant messaging.
We could not verify a free tier. Pricing listed at our last review: “One-time purchase · $6.99”.
Altapp's independent Trust Report (last full review Jul 17, 2026) shows 8/9 checks passed, covering source verification, data & permissions, and known risks. Verification reflects the version listed on this page.
iOS 17+ · Android · macOS · Windows · Linux.
Signal, Telegram, Proton Mail — each with its own verified Trust Report on Altapp. See the full list ›
Developers: get the Altapp Verified badge ›