Z Messenger

Z is a messenger built on one idea: the server should know nothing. There is no sign-up. No phone number, no email, no username, no password. Your identity is a cryptographic key pair generated on your device the first time you open the app — it never leaves your device unencrypted, and nobody, not even us, holds a copy. END-TO-END ENCRYPTED, ALWAYS Every message and attachment is encrypted on your device with a Signal-style double ratchet before it leaves, and only your contact's devices can decrypt it. There is no "secret chat" mode, because every chat is the secret mode. A SERVER THAT STORES NOTHING Messages travel through a relay that holds only undecipherable ciphertext, addressed to anonymous mailbox IDs, in RAM, until they're delivered — then they're gone. Nothing is ever written to a database or a disk. A complete copy of the server would reveal no messages, no names, and no list of users, because none of that exists there. ALL YOUR DEVICES, ONE IDENTITY Link your desktop or a second phone by comparing a short safety code between the two screens. Your chats, photos and files stay in sync across your own devices — still end-to-end encrypted. Lost a device? Revoke it with one tap and every contact's app immediately stops trusting it. BUILT TO BE VERIFIED, NOT TRUSTED • Compare safety numbers with a contact in person to rule out interception • Disappearing messages, from 30 seconds to a week • Encrypted attachments up to 24 MB, integrity-checked end to end • Local vault encrypted with XChaCha20-Poly1305, key held in your device's hardware keystore, with an optional app passphrase • Content-free notifications: the push wake-up contains no message and no sender — your device fetches and decrypts privately • Published, auditable source code — signed releases with SHA-256 checksums RUN IT YOURSELF IF YOU WANT Don't want to use our relay? Host your own with one Docker command and point the app at it. The full source is published for anyone to audit, and the license expressly permits personal self-hosting. Z is for people who think privacy should be the default, not a feature.