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SimpleX Chat
London, United Kingdom
What it is
SimpleX Chat is a messaging application for Android, iOS, Linux, macOS and Windows, with a free plan. Its network assigns no user profile identifiers, including phone numbers or usernames. Messages and metadata use end-to-end encryption with continuous post-quantum key exchange. Each chat uses four servers so relay servers cannot observe which IP addresses communicate. Profiles, contacts and messages are stored in a portable encrypted database on users’ devices; relay servers temporarily hold encrypted messages until delivery. The apps support encrypted text with Markdown and editing, media and file sharing, decentralized groups, voice messages, disappearing messages, and audio and video calls. Users can run their own SimpleX servers and communicate with people using preconfigured servers. Developers can use the open protocol’s SDKs for bots and integrations, including a TypeScript SDK that connects to the CLI through a WebSocket API. A mobile device can link to the desktop app only when both are on the same local network. Disappearing messages and deletion on recipients’ devices cannot be guaranteed when a device is offline or runs modified software.
For and against
For
- No user profile identifiers are assigned.
- Messages and metadata use end-to-end encryption.
- Supports voice messages and audio and video calls.
- Users can run their own SimpleX servers.
Against
- Desktop linking requires both devices on one local network.
- Recipient-side deletion cannot be guaranteed in some cases.
The verdict
SimpleX Chat combines messaging and calls with an identifier-free network design and device-side encrypted storage. Note the local-network requirement for linking mobile and desktop, and the limits on enforcing message deletion.
Who it suits
It suits people looking for messaging across mobile and desktop platforms, with encrypted messages, calls and groups. It may also suit users who want to self-host servers or developers building integrations.
Plans and prices
Free
No subscription charge stated
Read 14 Oct 2026 · shieldcue.com
SimpleX Chat
everything free; paid features planned
Read 1 Oct 2026 · simplex.chat
On the record
- API and SDK
- The open SimpleX protocol includes an SDK for building chat bots and services that users access through SimpleX Chat apps.simplex.chat · read 14 Oct 2026
- Audio and video calls
- The platform supports end-to-end encrypted audio and video calls and can use self-hosted WebRTC relays.simplex.chat · read 14 Oct 2026
- Company identity
- Crunchbase identifies the legal name as SimpleX Chat, Inc., founded in 2021, with headquarters in London, England, and founder Evgeny Poberezkin.crunchbase.com · read 14 Oct 2026
- Company size
- LinkedIn lists SimpleX Chat as a privately held technology company with 2–10 employees.linkedin.com · read 14 Oct 2026
- Company status
- SimpleX Chat Ltd is a UK-registered company developing communication software for the SimpleX network.simplex.chat · read 1 Oct 2026
- Crowdfunding news
- SimpleX announced an equity crowdfunding round on Wefunder on August 20, 2026, stating that the app had exceeded three million downloads and about 480,000 monthly users.simplex.chat · read 14 Oct 2026
- Data storage
- Profiles, contacts and messages are stored on client devices in a portable encrypted database, while relay servers temporarily hold encrypted messages until delivery.simplex.chat · read 1 Oct 2026
- Deletion limitation
- Message deletion and disappearing-message behavior cannot be guaranteed on recipients’ devices if they are offline or run modified software.simplex.chat · read 14 Oct 2026
- Desktop linking limit
- A mobile device can link to the desktop app only when both devices are connected to the same local network.simplex.chat · read 1 Oct 2026
- Developer documentation
- Documentation covers protocol schemas, terminal CLI operation, relay deployment, chat relays, calls, channels, privacy, and security settings.simplex.chat · read 14 Oct 2026
- Developer integrations
- The open protocol provides SDKs for chat bots and integrations, including integration of the SimpleX Chat library into mobile apps.simplex.chat · read 1 Oct 2026
- Disappearing messages
- Chats support disappearing messages with opt-out controls per contact or group.play.google.com · read 14 Oct 2026
- Download requirements
- Official desktop builds include Linux AppImage or Flatpak, Ubuntu 22.04/24.04 and Debian-based systems, macOS Intel or Apple Silicon, and Windows x86_64.simplex.chat · read 14 Oct 2026
- Encrypted media
- Users can send encrypted images and files, plus encrypted voice messages of up to five minutes.play.google.com · read 14 Oct 2026
- Encrypted portable database
- The app stores an encrypted portable chat database that can be transferred with contacts and history to another supported device.apps.apple.com · read 14 Oct 2026
- Encryption
- The network uses end-to-end encryption with continuous post-quantum key exchange for messages and metadata.simplex.chat · read 1 Oct 2026
- End-to-end encryption
- Messages, files, voice messages, and calls are end-to-end encrypted so relay servers cannot decrypt their content.shieldcue.com · read 14 Oct 2026
- Funding
- SimpleX announced a $1.3 million pre-seed round led by Jack Dorsey with participation from Asymmetric Capital Partners in August 2024.simplex.chat · read 14 Oct 2026
