SimpleX Chat: secure messenger

SimpleX - the first messaging network without user identifiers of any kind (not even random numbers) - 100% private by design!

Security assessments by Trail of Bits:
2022: https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html
2024: https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html

SimpleX Chat features:
- quantum resistant end-to-end encrypted messages, with editing, replies and deletion.
- disappearing messages with opt-out per contact/group.
- message reactions.
- delivery receipts, with opt-out per contact or group.
- multiple chat profiles, with hidden profiles.
- app access and self-destruct passcodes.
- incognito mode - unique to SimpleX Chat.
- end-to-end encrypted images and files.
- voice messages up to 5 minutes – also end-to-end encrypted.
- "live" messages – they update for all recipients as you type them, every few seconds - unique to SimpleX Chat.
- connect via one-time invitation links or via long-term public addresses.
- secret chat groups - only group members know the group exists and who is the member.
- end-to-end encrypted audio and video calls.
- connection security code verification, for contacts and group members – to protect from man-in-the-middle attacks (e.g. invitation link substitution).
- end-to-end encrypted push notifications (they contain only encrypted meta-data, not the actual content).
- encrypted portable chat database - you can transfer your chat contacts and history to another device.
- all local files and media are encrypted by default.
- animated images and "stickers" (e.g., from GIF and PNG files and from 3rd party keyboards).

SimpleX Chat advantages:
- privacy of your identity, profile, contacts and metadata: unlike any other existing messaging platform, SimpleX uses no phone numbers or any other identifiers assigned to the users - not even random numbers. This protects the privacy of who you are communicating with, hiding it from SimpleX platform servers and from any observers.
- complete protection against spam and abuse: as you have no identifier on SimpleX platform, you cannot be contacted unless you share a one-time invitation link or an optional temporary user address.
- full ownership, control and security of your data: SimpleX stores all user data on client devices, the messages are only held temporarily on SimpleX relay servers until they are received.
- decentralized proxied peer-to-peer network: you can use SimpleX Chat via your own relay servers and still communicate with people using pre-configured or any other SimpleX relay servers.
- fully open-source code.

You can connect to anybody you know via link or scan QR code (in the video call or in person) and start sending messages instantly - no emails, phone numbers or passwords needed.

Your profile and contacts are only stored in the app on your device - relay servers do not have access to this information.

All messages are end-to-end encrypted using