Threema messenger is open source as of today

Threema is a Swiss messaging app, that was particularly well-known in German speaking countries. It was well known for it privacy focus. Only downside - until now - was the fact that the app was proprietary. As of today, it seems Threema is open source software. Here is the company announcement:

At least until now Threema is not for free, it costs a one time payment. Therefore the app is NOT freely available in the /e/ AppsStore - but it can be purchased directly on the company’s website (or on Google Play).

In terms of its privacy focus, sole major competitor (I believe) is Signal. For further reading, check out this website:

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone


For German speakers:


Thank you for the information. I love Threema :grinning:

It is probably important to mention that Threema is funded through the purchase of their app and services. This means they are not dependent on angel funding like Signal. While Signal is VERY well funded for the foreseeable future, this means their funding could dry up, just like Telegram.

I’m a firm believer that you should pay for software, and so I think Threema is superior to Signal for some of these reasons. I also much prefer the fact that you can register an account without using your phone number.


I have been intrested in Threema for awhilst now, so was greatful to see this post announcing it now open source and 50% off. Today i decided i would buy multiple licences as gifts… HOWEVER im on android and my friends and family are on IOS. I can purchase mutliple licences through the Threema store for Android but it wont let me mix and match operating systems, instead it says to use the apple store, which is extremley frustrating as i dont have an iphone. It would have been better if it let me buy all the licences and then send them to whom-ever so they can activate their device. I was even going to contact their customer support to suggest for them to make it easier, however there is no easy method to contact them as i have to select a number of drop down boxes all of which dont direct my enquiry, and wont progress until the red writing goes way, so ive given up… this would have made a great Christmas stocking filler digital gift but alas it is not to be… :frowning_face:

I’m pretty sure this is due to Apple’s policy, AFAIK everything has to go through their App store. They just don’t allow any alternatives.


Good to hear!
I would like to install Threema on my /e/ smartphone, but in App Store I only find Threema Work. But I only have a licence for Threema “normal”.
Any hint how to install the normal threema version on /e/ smartphone?

Insert your licence here , download the APK file and install it.


THX a lot.
It worked :slight_smile:

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I dont know if i am the only one, but i have got problems with incoming calls with Threema… when Threema is in the background, i dont get any notification, when called from a Threema-contact… i do get notifications for incoming messages - always…

But Threema in general is really good and i love the fact, that they are now open source…

Is it federated also? And does the app automatically find people in your address book who also have Threema?

@Rik, it is a centralized service. There’s a feature to find people in your address book - in case they want to be found and and registered with a phone number (there’s a way to register with another identifier).


Have they ever commented in what they will do if someone starts a fork, in terms of federating?

For now only the messenger app is open sourced, the server software not (yet).

haha ok, well good step, but the server is where everything happens!

That’s actually a question I am asking myself with regards to Wire - as they have published server-side as well as user-side software as open source.

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ask them! im sure they will respond

I don’t know Threema enough to compare, but Id’ say one should compare it to

  • Signal : open source, end-to-end encyption, demanding a GSM phone # to start, featuring a central server so in theory some powerful ‘external observer’ can know who you are calling, even if unable to listen or read the message, easy to install. On a phone Signal also can take on all SMS activity, those encrypted but the ordinary ones as well
  • Jami : less easy to install (one must create an identity), open source, end2end encryption, available on phones and linux/mac/win (so no absolute need for a phone #), no central server so not only your messages cannot be read but nobody can tell who you are communicating with.

I don’t know how Threema compares on these criteria. But i’m going to have a look.
(incidentally, the fact that the ‘Boxcryptor’ website doesn’t mention Jami is a significant compentence weakness IMHO)
I use Signal daily, Jami less often (less correspondents)

Signal does this. Jami doesn’t since it is not linked to a phone # (you can send email invites for instance)

I just installed and cannot confirm this. Give yourself a user name, add a password for encryption and optianally add your name. Easy enough methinks?