End-to-end encrypted
Messages stay between you and the people you talk to.
LockerChat is a private messenger. Message bodies are encrypted end-to-end and the server only ever sees ciphertext. Encryption keys never leave your devices.
Every message, every device
Ciphertext + metadata only
Sign up with a username
Run it on your own box
A messenger built around what you don't share
No phone-number signup. No address-book sync. No targeted-ad data.
True end-to-end encryption
Per-device keypairs. Every message is encrypted to each recipient device with libsodium sealed-boxes. The server can't read a thing.
No phone number, no email
Sign up with a username. No phone-number lookup, no contact-book sync, no public directory.
Apps for everywhere
Native iOS and Android via Expo, plus a fast React web client. Linked devices share a session over an 8-character code.
Disappearing messages
Per-group TTL. The server sweeps expired messages every minute and clients purge locally.
Attachments & voice
Images, files, voice notes. All encrypted client-side before upload. The server only ever sees an opaque blob and its key envelope.
Threads, reactions, mentions
The features you'd expect from a modern messenger, without giving up the privacy guarantees. Lockscreen Mark-read & Reply on Android.
The server can't read your messages
Every message body is sealed to your recipients' devices before it leaves yours. The server only ever handles ciphertext.
- libsodium crypto_box_seal per recipient device
- X25519 device keys, never leave the device
- Argon2id-hashed passwords for account recovery only
Feature screenshot
No public directory
No public user search. No phone-number lookup. No address-book sync. No “people you may know.”
- Sign up with a username, not a phone number
- No email, no contact-book uploads
- Group membership stays inside the group
Feature screenshot
Multi-device, no compromises
Add an iPhone, an Android, a tablet, the web app. Each gets its own keypair, and messages are encrypted to every active device. Linking a new device is an 8-character code or a QR scan.
- Per-device sealed-box envelopes (keys never leave the device)
- 8-char Crockford base32 link codes for new-device setup
- Tablet split view, system light/dark theme, lockscreen actions
Feature screenshot
Built to be open
The protocol is specified end to end: threat model, frame types, and JSON envelopes. We'll publish the spec alongside the public release so the design can be reviewed.
- A written spec behind every endpoint and WS frame
- An explicit threat model: what we protect, what we don't
- Self-hostable: run your own server, your own keys
Feature screenshot
A small messenger for the people you talk to most.
LockerChat isn't open to the public yet. Read the threat model, or check back soon.