Briar

Decentralized Application

A messaging app for activists, journalists and anyone who needs a safe and robust way to communicate. Unlike conventional messengers it has no central server: messages are synchronised directly between users' devices. If the internet is down, Briar can sync over Bluetooth, Wi-Fi or memory cards; if it is up, it syncs over the Tor network to hide who is talking to whom. Briar Mailbox lets users who are online at different times exchange messages. Alongside private messaging it offers public forums and blogs, each user's contact list is encrypted and stored on their own device, and all communication between devices is end-to-end encrypted. Briar is for Android, with a desktop version in development .

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Details

License Copyleft (GNU General Public License, per the licence text in the repository). https://code.briarproject.org/briar/briar (primary), mirrored at https://github.com/briar/briar
Dev Status 🟢 Active
Owner The Briar Project, governed by a voluntary board; Michael Rogers started the project, with Eleanor Saitta, Torsten Grote and other contributors named on its About page
Governing Body A voluntary board, with a published governance page and a code of conduct
Country Not stated by the project.
Start Year 2011
Stack Java and Kotlin (Android) with the Bramble libraries in the repository, Tor for internet transport, Bluetooth and Wi-Fi transports, and a separate Briar Mailbox component
Funding Grants and donations: the project lists the Small Media Foundation, Open Internet Tools Project, Access Now, Open Technology Fund, Prototype Fund, Internews, NLnet Foundation, the Next Generation Internet programme, the ISC Project and eQualit.ie
Last Investigated Oct 29, 2026

Use Case Domains

Communication Platform Evolution & Sovereignty

Affordances

End-to-end encrypted Works offline / mesh Self-hostable

Decentralized Application Attributes

Origins Communication that survives surveillance and censorship and does not need the internet: built for activists and journalists, using Tor for metadata protection and Bluetooth, Wi-Fi and memory cards when connectivity is down
Database Local encrypted database on each device; no server-side storage
Query Language N/A
Data Formats Bramble synchronisation protocol messages between peers; the technical details are on the project wiki
Collaborative Live Editing N/A
Rich Text Editing Not stated by the project.
Mobile Support Yes: Android, via F-Droid, Google Play and a direct APK
Web Support No web client was described in the cited sources
Native Apps Android app; Briar Desktop is under development by contributors
Terms Free and open source (GPL); the project accepts donations
Funds Not stated by the project.
Based On Tor for anonymity; the Bramble transport and synchronisation protocols developed by the project; public-key cryptography for contacts
Use Case Category Private messaging, public forums and blogs for activists and journalists
User Interface Type Android app; desktop client in development
Offline Capabilities Strong: syncs over Bluetooth, Wi-Fi or memory cards when the internet is unavailable
Collaboration Features Private chats, private groups, forums and blogs
Data Portability Not stated by the project.
Integration Ecosystem A headless mode and a mailbox component exist in the repository; no third-party integration was described in the cited sources
Web2 Data Export Not stated by the project.
Prosocial Coherence Not stated by the project.
Economic Flows None: no payment, token or marketplace feature.
Governance & Decision Making A voluntary board governs the project, with a code of conduct for contributors
Media / Publishing N/A
Knowledge Management N/A
Sensemaking N/A
Project Management N/A
Communication Model Peer-to-peer synchronisation of encrypted messages between devices, over Tor, Bluetooth or Wi-Fi, with an optional mailbox for users who are online at different times
Network Resilience High: it works without internet via Bluetooth, Wi-Fi or memory cards and with Tor when the internet is censored or monitored
Discovery Mechanism Contacts are added in person (QR code) or by link; no central directory
Max Participants Not stated by the project.
Data Sovereignty High: data and the contact list stay on the user's device and are encrypted