SimpleX

simplex-chat

Security assessment was done by Trail of Bits in November 2022.

SimpleX Chat features:

• end-to-end encrypted messages, with editing, replies and deletion of messages.
• sending end-to-end encrypted images and files.
• single-use and long-term user addresses.
• secret chat groups - only group members know it exists and who is the member.
• end-to-end encrypted audio and video calls.
• private instant notifications.
• portable chat profile - you can transfer your chat contacts and history to another device (terminal or mobile).
• encrypted app database and files in the app storage (except videos).
• 18 interface languages.

SimpleX Chat advantages:

• Full 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 network: you can use SimpleX with your own servers and still communicate with people using the servers that are pre-configured in the apps or any other SimpleX servers.

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 - our servers do not have access to this information.

All messages are end-to-end encrypted using open-source double-ratchet protocol; the messages are routed via our servers using open-source SimpleX Messaging Protocol.

Please send us any questions via the app or submit an issue on GitHub.

Follow us on Mastodon, Twitter and Reddit for the latest updates.

Once you install SimpleX Chat, "connect to developers" for any questions, to share feedback, and to discover the groups (the link for directory service will be in response).