Alternatives / Threema
Looking for an open source Threema alternative? Only one project we verified fits: Signal, an encrypted messenger run by a nonprofit. Unlike Threema, it requires a phone number to register.
Written by Maxime DERAME
Last updated:
| Alternative | Best for | License |
|---|---|---|
| Signal | Nonprofit-run encrypted messenger | AGPL-3.0 |
We looked for open-source encrypted messengers. We verified Signal's license, recent activity, stars, and platforms in its repository. See our methodology for the full criteria.
Signal provides end-to-end encrypted messaging, voice and video calls, group chats, and media sharing, with no ads, affiliate marketing, or tracking. It is run by a nonprofit funded by grants and donations and uses your phone's data connection.
Signal requires a phone number to register, which Threema does not. Its server is not designed for easy self-hosting.
The Signal Android app is AGPL-3.0.
Signal is actively maintained.
Threema is a paid messenger from a Swiss company with open-source apps. Signal is free and based on the open Signal Protocol, but it ties accounts to phone numbers.
Open-source messaging applications, server, and cryptographic libraries with end-to-end encryption enabled by default using the Signal Protocol. Features include private messages, groups, voice messages, file and media sharing, disappearing messages, voice and video calls, group calls, stories, usernames, and desktop applications. The official service is centralized rather than federated.
Pricing: Free messenger operated by the nonprofit Signal Foundation.
| Alternative | Type | License | Self-hosted | Best for |
|---|---|---|---|---|
| Signal | Messenger | AGPL-3.0 | No | Private everyday messaging |
Want an encrypted messenger
Signal uses the open Signal Protocol and is run by a nonprofit.