Threema. The Secure Messenger

Review by eFreeware

Most messengers ask for your phone number before you can send a single message. Threema takes the opposite route: a randomly generated Threema ID stands in for your number or email address, so you can use it without handing over either. That single design choice shapes everything else about the app, and it is the reason I would start any look at it here.

The developer, Threema AG, has been running this app since May 2013 and puts the current install count above five million, with a 3.9 average across more than 75,000 ratings. Those are the numbers of an established product rather than a new arrival, and the pitch is narrow on purpose: chats, calls and files with encryption throughout and what the developer describes as no data trail left behind.

This is not a messenger for everyone. It is for readers who treat their contact list, call history and shared files as private material and would rather pay a one-time price. If your main concern is being where all your friends already are, the anonymous ID model asks something of them too, and that is worth weighing before you spend the money.

The anonymous ID as the center of the design

Instead of signing up with a phone number or email address, you get an ID made up of random characters. The developer presents anonymous use as a core feature rather than an afterthought, and it changes the social side of messaging: you share that ID with the people you want to reach, and they add you with it.

Contacts can be verified by scanning a QR code, which lets two people confirm they are talking to the right identity rather than trusting a typed-in string of characters. For anyone who has ever worried about a mistyped or spoofed contact, that is a small step that makes a real difference.

The trade-off is practical rather than technical. An ID you have to pass along is a slower start than a messenger that reads your existing address book and finds everyone at once, and the people you message have to be willing to install the app and make the same choice. Threema is built for a contact list you have deliberately assembled.

Messaging, calls and files under one roof

The everyday layer is familiar enough: text and voice messages with emoji reactions, plus voice, video and group calls, all of it encrypted end to end according to the developer. Sent messages can be edited, and they can be deleted for the people you were chatting with, which covers the two mistakes most of us make in a hurry.

File sharing is broader than I expected from a privacy-first app. The app supports all formats, with PDF, GIF, MP3 and ZIP named as examples, so sending a document or a compressed folder is part of the normal flow rather than a workaround. Location sharing is included as well, for the times when a pin on a map says more than a paragraph of directions.

Groups get their own tools: you can create them and run polls inside them, which is the sort of feature that turns a chat app into something a club, a team or a family can actually organize around. A light or dark mode rounds out the interface options, and a desktop app and web client let you carry the same conversations over to a PC when typing on a phone stops being convenient.

What the security claims rest on

The security story is not just about encryption on the wire. The code is open source, it undergoes regular audits, and the servers sit in Switzerland. Once a message has been delivered, it is removed from the server right away, which limits what is left behind.

Taken together, those are the claims to weigh rather than take on faith. Open source and audits can be checked by people qualified to check them; server location and immediate deletion are statements about how the service is run. The whole product is built around privacy rather than adding a lock icon to a conventional messenger.

The app also states that there is no ad tracking and no data collection of the kind that funds free messengers.

What you pay, and what you do not

Threema costs $7.49 as a one-time purchase. There are no ads in the app and no in-app purchases, so the price you see is the whole of it. For a messenger, that is an unusual arrangement: much of the category is free and funded by advertising or subscriptions.

I find the model easy to respect. You are paying for the product rather than being the product, and the developer's emphasis on having no trackers or data collection fits with charging up front instead of monetizing attention later.

The flip side is that $7.49 is a real barrier in a category where the default assumption is zero. Multiply it by a household or a group of friends and the cost of switching becomes a group decision, not a personal one. Whether that is reasonable depends on how much you value the anonymity and the absence of advertising, and only you can price that.

How it compares with the free options

Against a mainstream free messenger, Threema trades reach for privacy. If your contacts are the deciding factor, the free option usually takes it.

Against other privacy-focused messengers, the difference is the payment model and the identifier. The QR verification and the desktop and web clients are the features I would compare side by side, since those are what you live with day to day.

The developer's claim of being the best-selling secure messenger, with more than 12 million users across over 175 countries, is the kind of figure that suggests a working product rather than an experiment.

A messenger for people who would rather pay than be tracked

It covers the ground a messenger needs to cover: messages, calls, groups, files, location and a way to chat from a computer, with encryption applied across all of it.

The case against it is not about missing features so much as friction. A randomly generated ID is more private than a phone number and less convenient than one, and a paid app in a free category asks for a decision before it has shown you anything. The 3.9 average across a large number of ratings suggests a settled, widely used product rather than a flawless one.

If you have been looking for a messenger that treats your contact list as yours, this is one of the few that makes that promise the center of the product rather than a setting. Install it if you are comfortable paying once, sharing an ID instead of a number, and bringing your regular contacts along with you.

What's new in version 6.5.3

- Fixed a bug related to automatic file downloads - Improvements to contact synchronization - Various improvements and bug fixes