secure messaging app · Threema GmbH

Threema

Messenger you buy once and use with a random Threema ID instead of a phone number.

79/100

#2 of 12 secure messaging apps
Facts checked 8 Oct 2026

In short

Threema Private for individuals costs a one-time $6; the price varies by app store and country¹.
You can use it without giving a phone number or email address; contacts reach you by Threema ID^5,6.
Cure53 audited the new desktop app in 2024, and the full report is published⁴.
Threema's transparency report covers 2014 to 2026, including 444 authority requests in 2026⁷.
The desktop app and web client work through your phone, which must be connected to the internet².

Threema suits people who want a one-time purchase and an account that is not tied to a phone number^1,5. Its code is public, it publishes audit reports, and it lists government requests each year^3,4,7. The catch: the usual desktop app and web client need your phone online, and only a beta works without it^2,13. Group chats are capped at 256 members¹⁴.

Best for: People who want a messenger with no phone number and no subscription.

Where the points come from

Encryption12 of 20

Source and audits26 of 26

Sign-up and identity16 of 16

Chats and calls7 of 14

Systems12 of 16

Price6 of 8

Encryption 12 of 20 points

Rule	What is published	Points
End-to-end encrypted by default	YesThreema says end-to-end encryption protects all communication, including messages, media, calls and group names and member lists^3,11.	12 / 12
Post-quantum key exchange	Not publishedNot published on the vendor's security page or encryption FAQ^3,11.	0 / 4
Encrypted backups	Not publishedA data backup is protected by a password you choose, but its encryption is not described¹⁰.	0 / 4

Source and audits 26 of 26 points

Rule	What is published	Points
Open-source apps	YesThreema says the app source code is public; the Android repository uses AGPL-3.0^3,8.	8 / 8
Independent audit since 2022	YesCure53 audited the new desktop app in 2024; the full report is linked⁴.	10 / 10
Public bug bounty	YesThreema runs a bug bounty on GObugfree, with published rewards from CHF 50 to 10,000^15,16.	4 / 4
Transparency report	YesThe report shows authority requests for 2025 and 2026, last updated 2026-06-30⁷.	4 / 4

Sign-up and identity 16 of 16 points

Rule	What is published	Points
No phone number needed	YesFAQ: you can use Threema without a phone number and email address⁵.	12 / 12
Contacts by username	YesEach user gets a random 8-digit Threema ID not tied to a phone number⁶.	4 / 4

Chats and calls 7 of 14 points

Rule	What is published	Points
Disappearing messages	Not publishedSupport FAQ lists an auto-delete setting (1 week to 1 year) but does not say it covers one-to-one chats and groups¹⁴.	0 / 5
Largest group chat	256Support FAQ: "Groups can contain up to 256 members." Group calls are limited to 16 people¹⁴.	2 / 4
Encrypted voice and video calls	YesThe calls FAQ says Threema calls are end-to-end encrypted, with video as an option in a call⁹.	5 / 5

Systems 12 of 16 points

Rule	What is published	Points
Apps	Windows, macOS, Linux, iOS, Android, WebDesktop app for macOS, Windows and Linux, a web client, and Android and iOS apps; no beta is named².	12 / 12
Windows works without the phone	NoThe desktop app and web client need the phone connected to the internet; only a beta works offline^2,12,13.	0 / 4

Price 6 of 8 points

Rule	What is published	Points
Cost for one person	$6/yrThreema Private, one-time $6 for an individual¹.	6 / 8

The rule behind each line: how we score secure messaging apps.

Plans and prices

As the vendor lists them, before tax. Prices are in US dollars unless the plan shows euros; the points use US dollars, with euros converted at the ECB rate.

Plan	Price as listed	Per month	Notes
Threema Private1 person	$6 one-time¹	–	Price depends on app store and country

The price page says the amount depends on the app store and country; business plans are priced separately and not counted¹.

Strengths

No phone number or email address is needed to register⁵.
Cure53 audited the new desktop app in 2024 and a university team analysed the Ibex protocol in 2023, both with published reports⁴.
Voice and video calls are end-to-end encrypted⁹.
The apps' source code is public, and the Android app is under AGPL-3.0^3,8.
A bug bounty runs on GObugfree, with rewards up to CHF 10,000^15,16.

Limits

It is a paid app; the pricing page lists only a one-time purchase¹.
The generally available desktop app and web client need your phone connected to the internet².
Offline desktop use exists only in a beta¹³.
Group chats hold up to 256 members, and group calls up to 16 people on Threema Private¹⁴.

Other secure messaging apps

1
SimpleX ChatPeople who want a messenger that holds no account identifier or phone number
86/100
$0cost for one person
3
WirePeople who want default encryption and open-source apps without handing over a phone number
78/100
$0cost for one person
4
ElementPeople who want open-source apps on every platform and no phone number
69/100
$0cost for one person
5
SignalPeople who want private chats by default and open-source apps, and accept sharing a phone number
67/100
$0cost for one person

Threema vs SimpleX Chat · Threema vs Wire · All 12 secure messaging apps

Sources

Threema pricing, Threema. Accessed 8 Oct 2026.
Threema Web and desktop, Threema. Accessed 8 Oct 2026.
Threema security, Threema. Accessed 8 Oct 2026.
Security audits, Threema. Accessed 8 Oct 2026.
Using Threema without a phone number, Threema. Accessed 8 Oct 2026.
Threema FAQ, Threema. Accessed 8 Oct 2026.
Transparency report, Threema. Accessed 8 Oct 2026.
threema-ch/threema-android, GitHub. Accessed 8 Oct 2026.
Threema calls, Threema. Accessed 8 Oct 2026.
Data backup, Threema. Accessed 8 Oct 2026.
Why Threema is secure, Threema. Accessed 8 Oct 2026.
Multi-device and desktop explained, Threema. Accessed 8 Oct 2026.
Threema desktop beta with multi-device support, Threema. Accessed 8 Oct 2026.
Threema Private support, Threema. Accessed 8 Oct 2026.
Is there a bug bounty program?, Threema. Accessed 8 Oct 2026.
Threema bug bounty program, GObugfree. Accessed 8 Oct 2026.

Website: threema.com · Markdown version · We are not affiliated with Threema GmbH.