Open source Threema alternatives

All Threema alternatives

1. 

   

   Signal

   4.7(1.1M) · App StoreLike

   Signal is a free, open-source messenger run by the nonprofit Signal Foundation. Messages, calls, group chats and media are end-to-end encrypted with the Signal Protocol, and the service is designed to collect as little metadata as possible. Registration requires a phone number, though usernames let you chat without sharing it, and the app has no ads or trackers.

   10 Signal alternatives

   Pros

   • Signal Protocol encrypts messages, calls and groups end to end
   • Run by a nonprofit, with minimal metadata and no ads
   • Usernames let you chat without revealing your phone number

   Cons

   • A phone number is still required to register
   • Fewer of your contacts are likely to use it than mainstream apps

   Cost / License

   FreeOpen source

   Categories

   Messaging Apps

   Platforms

   WindowsMacLinuxiPhoneAndroid

   Features

   Ad-freeDisappearing messagesEnd-to-end encryptionGroup chatsVoice and video calls

   Visit websiteMore about Signal
2. 

   

   Session

   4.4(5.2K) · App StoreLike

   Session is an open-source, end-to-end encrypted messenger that needs no phone number or email: an account is just a randomly generated Session ID. Messages are relayed through a decentralized network of community-operated nodes using onion routing, which hides IP addresses and limits metadata. It supports one-to-one chats, small private groups and larger communities on desktop and mobile.

   9 Session alternatives

   Pros

   • No phone number or email: an account is just a random Session ID
   • Onion routing hides IP addresses and limits metadata
   • Decentralized network of community-operated nodes

   Cons

   • Messages can arrive more slowly than on centralized apps
   • Small user base compared with mainstream messengers
   • Losing your recovery phrase means losing your account

   Cost / License

   FreeOpen source

   Categories

   Messaging Apps

   Platforms

   WindowsMacLinuxiPhoneAndroid

   Features

   Ad-freeDisappearing messagesEnd-to-end encryptionGroup chatsNo phone number required

   Visit websiteMore about Session
3. 

   

   SimpleX Chat

   4.3(271) · App StoreLike

   SimpleX Chat is an open-source messenger that does not assign users any identifier, not even a random one: contacts connect through one-time links or QR codes. Messages are end-to-end encrypted and pass through relay servers that keep no user profiles, and anyone can run their own relays. It supports groups, voice and video calls, disappearing messages and multiple chat profiles.

   9 SimpleX Chat alternatives

   Pros

   • No user identifiers at all, not even random ones
   • Anyone can run their own relay servers
   • Groups, calls, disappearing messages and multiple chat profiles

   Cons

   • Connecting through one-time links is less convenient than a contact list
   • Small user base, so few contacts will already be on it
   • Using one account across several devices is limited

   Cost / License

   FreeOpen source

   Categories

   Messaging Apps

   Platforms

   WindowsMacLinuxiPhoneAndroidSelf-hosted

   Features

   Disappearing messagesEnd-to-end encryptionGroup chatsNo phone number requiredVoice and video calls

   Visit websiteMore about SimpleX Chat
4. 

   

   Olvid

   4.5(42) · App StoreLike

   Olvid is an end-to-end encrypted messenger developed in France that works without a phone number, email address or central user directory: contacts are added by exchanging codes in person or through trusted introductions. Its security has been certified by ANSSI, the French cybersecurity agency, and its apps are open source. Messaging is free, with paid subscriptions for advanced features and for businesses.

   8 Olvid alternatives

   Pros

   • No phone number, email or central user directory required
   • Security certified by ANSSI, the French cybersecurity agency
   • Open source apps on desktop and mobile

   Cons

   • Adding contacts in person or via introductions slows onboarding
   • Small user base, so most contacts will need to install it
   • Advanced features and business use require a subscription

   Cost / License

   FreemiumOpen source

   Categories

   Messaging Apps

   Platforms

   WindowsMacLinuxiPhoneAndroid

   Features

   Ad-freeEnd-to-end encryptionGroup chatsNo phone number requiredVoice and video calls

   Visit websiteMore about Olvid
5. 

   

   Telegram

   4.0(282.8K) · App StoreLike

   Telegram is a cloud-based messaging app that syncs chats across phones, desktops and the web, with very large groups, broadcast channels and an extensive bot platform. Its client apps are open source, but the server is not, and only the optional Secret Chats are end-to-end encrypted. Telegram Premium adds extras such as bigger uploads and faster downloads.

   10 Telegram alternatives

   Pros

   • Cloud sync across phone, desktop and web
   • Huge groups, broadcast channels and a powerful bot platform
   • Open source clients that are fast and polished

   Cons

   • Regular chats are not end-to-end encrypted, only Secret Chats are
   • Secret Chats do not sync across devices and are unavailable in groups
   • Server code is closed, unlike the client apps

   Cost / License

   FreemiumOpen source

   Categories

   Messaging Apps

   Platforms

   WebWindowsMacLinuxiPhoneAndroid

   Features

   API accessChannelsCross-device syncGroup chatsVoice and video calls

   Visit websiteMore about Telegram
6. 

   

   Element

   3.3(590) · App StoreLike

   Element is a messaging app from the team that created Matrix, an open standard for decentralized, federated chat. Rooms, direct messages and calls are end-to-end encrypted, and people on different Matrix servers can talk to each other like email. Individuals can join a public server for free, while organizations and governments self-host or buy Element's enterprise server suite, with bridges to other chat networks.

   12 Element alternatives

   Pros

   • End-to-end encryption by default for private rooms and messages
   • Federated Matrix network, so no single company controls your chats
   • Open source and self-hostable, popular with public sector bodies

   Cons

   • Encryption keys and device verification can confuse newcomers
   • Running your own Matrix server takes real technical effort
   • Fewer business integrations than mainstream team chat apps

   Cost / License

   FreemiumOpen source

   Categories

   Team ChatMessaging Apps

   Platforms

   WebWindowsMacLinuxiPhoneAndroidSelf-hosted

   Features

   ChannelsEnd-to-end encryptionNo phone number requiredThreaded conversationsVoice and video calls

   Visit websiteMore about Element