$ plaintxt --how-it-works

how it works

no accounts. no servers storing your plaintext. here's exactly what happens.

// from browser to message

you open plaintxt

no install, no login screen. the app loads entirely in your browser. nothing is downloaded to your device.

pick a username

choose any available username. it is yours until you burn it — no expiry, on any plan. burning it releases the name for someone else to claim.

key pair is generated locally

your browser generates an ECDH P-256 key pair. your private key is stored in IndexedDB — it never leaves your device, not even to our servers.

public key goes to the server

only your public key is uploaded. the server uses it to route encrypted messages to you. it cannot use it to decrypt anything.

you send a message

your browser fetches the recipient's public key, derives a shared secret using ECDH, and encrypts the message with AES-256-GCM. the server receives ciphertext only.

recipient decrypts locally

when the message arrives, the recipient's browser uses their private key to derive the same shared secret and decrypt. the server is never involved in decryption.

you decide when it is gone

messages stay until someone deletes them. delete a message, a conversation, or your whole identity and it is hard-deleted from the server — no archive, no undo. power users can opt a conversation into burn-after-read, which deletes each message 60 seconds after it is read.

identity expires and is gone

when your identity expires, all messages, sessions, and keys are hard-deleted from the database. there is no archive. there is no recovery unless you have a Pro/Power recovery code.

// smart read detection

messages only mark as read when all three conditions are met simultaneously:

tab: the plaintxt tab is the active foreground tab

window: the browser window is focused (not minimized or behind)

dwell: the conversation has been open for at least 1.5 seconds

this prevents accidental reads from notification previews or tab switching. the burn timer only starts when you're actually looking at the message.

// what the server sees

server stores

• your username

• your public key

• message ciphertext

• timestamps

• session token (hashed)

server never sees

• your private key

• message plaintext

• your real identity

• your IP (Cloudflare proxies)

• any personal data