Why isn’t Threema free of charge?

The development of the Threema apps and the maintenance of the server infrastructure generates costs. The app price covers these costs.

If we wanted to offer our apps for free, we would have to monetize user data, which, of course, would totally undermine Threema’s purpose (i.e., to protect the users’ data and privacy). Besides, Threema is designed from the ground up to only generate as little user data as technically possible, so there’s next to no user data to begin with.