SimpleX Chat is a messaging platform built in Haskell that fundamentally reimagines privacy in communication by operating without any user identifiers. The core innovation is that the system contains no usernames, phone numbers, or other persistent identifiers that could be used to track or identify users, making it private by design rather than through optional settings.
The platform implements double-ratchet end-to-end encryption with an additional encryption layer to protect both message content and metadata, including information about who communicates with whom and when. Connections between users are established through shared links or QR codes that must be exchanged through a separate channel, whether secure or not, with the security guarantee coming from the ability to verify the connection's authenticity rather than from the link itself.
SimpleX Chat is available across multiple platforms including iOS through the Apple App Store and TestFlight preview program, Android via Google Play and direct APK downloads, and as a terminal application for Linux, macOS, and Windows. The TestFlight preview provides access to new features one to two weeks before general release but is limited to ten thousand users.
According to GitGenius tracking data, the repository has demonstrated steady growth with stargazers increasing from seventeen thousand eight hundred thirty-five to seventeen thousand eight hundred thirty-nine between July fourth and the most recent check. The project maintains active development with a median issue and pull request response latency of zero hours and a mean latency of one hundred three point five hours across one thousand eighty-seven tracked items. The most active issue labels are enhancement with five hundred nine items, triage with four hundred ninety-two items, and bug with three hundred eighty-five items. Narasimha-sc leads contributor activity with one thousand six hundred seventy tracked events, followed by epoberezkin with three hundred eleven events and serrq with three hundred six events.
The repository overlaps with contributors from major projects including Microsoft's Visual Studio Code, the Rust programming language, and Microsoft's TypeScript, indicating involvement from developers across significant open-source ecosystems. The project has received security validation through a Trail of Bits security audit and is recommended by privacy-focused organizations including Privacy Guides and Whonix.
The platform supports group messaging and community features through a SimpleX Directory where users can discover and create groups. The development team actively engages with users through multiple channels including Reddit, Twitter, Lemmy, Mastodon, and Nostr, and maintains a blog with RSS feed for updates. The project welcomes contributions including chatbot development, feature implementation, and translation work through Weblate, with documentation available for users and developers interested in building on the SimpleX platform.
