Notes 
No native desktop apps available yet, but there is a web version for your browser. No phone number is required to signup but there is a payment involved to get the app. Fortunately the Threema shop accepts Bitcoin.
Reviewed by Gabriel Bachmann
Threema
threema.ch 4.2 (10)
Rate Threema: No account needed
Threat level
Hardened
A hardened pick. Worth the effort once you have chosen to shrink your footprint on purpose. Enough for most people. Threat levels
Our take
Paying for a messenger feels backwards until you realize the upfront purchase, with no phone number or email needed, is exactly what lets it avoid harvesting you. The cost is twofold: the price itself filters out most contacts, and desktop is web-only rather than native. A genuinely good pick for privacy-minded buyers in its Swiss orbit; a hard sell for getting a whole friend group on board.
GitHub at a glance
threema-ch/threema-android AGPL-3.0 android-appmessagingmobile-appsecure-messenger
Stars
1,005
+0 this week
Forks
118
55 watching
Last commit
today
healthy
Star history
Commits, last 26 weeks
5 commits, active 5 of 26 weeks
0 contributors since Dec 2020
Languages
- Kotlin 53.4%
- Java 39.5%
- Rust 6.8%
Updated daily from the GitHub API. Star tracking since Jun 15, 2026.
Website at a glance
threema.ch
B score 70
Solid website security headers
Graded by Mozilla HTTP Observatory, tested 12d ago
Inspect this site yourself
Measures the security configuration of the tool's own website, not the privacy of the product itself. A strong tool can still score low here.
Threema alternatives
Signal Similar look and feel of WhatsApp and other commonly used messaging apps, makes switching easy. Signal requires your phone number as an personal identifier.
Delta Chat Delta Chat doesn't have their own servers but uses the most massive and diverse open messaging system ever: the existing e-mail server network. Chat with anyone if you know…
Brave Talk The person creating the call requires to use Brave Browser, but the participants can join from any browser.
Jitsi Meet Desktop version downloads can be found here .
Stoat Open source, self-hostable Discord alternative, formerly Revolt. Built for communities that want off Discord, but it is not end-to-end encrypted.
iMessage Apple's built-in messenger. End-to-end encrypted between Apple devices.
Threema license, in plain English
AGPL-3.0 Strong copyleft · network
Free to use, even commercially. Changes must be published under the same license, and running a modified version as a network service counts as distributing it.
Permits
- Commercial use
- Modification
- Distribution
- Patent use
- Private use
Requires
- Disclose source
- Network use is distribution
- Same license
- State changes
- License and copyright notice
Does not provide
- Liability cover
- Warranty
Why it matters: The network clause is the point. Anyone who runs a modified version as a hosted service has to publish those changes, so the code handling your data stays inspectable. This is why privacy-first projects reach for AGPL.
Plain-language summary of the project's license, not legal advice. Read the full text for the exact terms.