Sealed before it leaves
Locked on your device for you and the other person. The server only keeps the sealed copy.
Side door, nine.
Copy.
v2 · B1a0cE3k9Qm27sL4pR8dW0uNxF6aY1cH5tZ
FREE · PRIVACY IS A RIGHT · CURRENTLY IN BETA
We store the lock.Not the conversation.
Blackout Chat is free, because privacy is your right. Advanced encryption locks every message on the devices before it is saved. Unlike other chat apps, no corporation or AI can see your messages.
Get Blackout ChatSign in
On the two devices
Side door, nine.
Copy. Burning in an hour.
On the server
from ·········
to ·········
body v2.n0.gAAAA
B1a0cE3k9Qm2
7sL4pR8dW0uN
xF6aY1cH5tZBurn timers
A message can disappear after five minutes, an hour, a day, or a week. Or you can keep it.
5m1h1d7dKeep
A real account
A password, then a handle people can search. On the backend, messages stay under extreme encryption. The server never holds the readable text.
@nightshift
Safety number
Compare it in person. If it matches, the handle is really them.
48291 10637
The screen stays locked
A passphrase unlocks this screen. That passphrase never goes to the server.
● ● ● ● ● ● ● ●
One recovery code
Shown once, for a new browser or a new app screen. Earlier messages stay on the device that already has them.
K7NP-4QWM-9HXC-2LVA
Notes to yourself
A sealed thread only this account can open.
Server view
OnSide door, nine.
v2.n0.gAAAA.B1a0cE3k9Qm27sL4pR8dW0uN
Flip it and the sentence is gone. This is the copy we keep.
Nearby
No Wi-Fi? The phones talk over Bluetooth. Those messages never upload.
YouThem
Passkey
Skip the passphrase. Unlock this device with a passkey.
It's a PWA (a progressive web app). You open it in the browser, then add it to your home screen. On your phone it runs like an app.
5m
It locks itself
After a few quiet minutes, or if you leave the tab, it locks. You type your passphrase to open it again.
MULTIPLE LOCKS
Different encryption, for different jobs.
X25519
The two devices agree on a secret. That secret is never sent.
HKDF
The secret is stretched into the separate keys the chat actually uses.
AES-256-GCM
The words are sealed. A changed copy will not open.
Double ratchet
The next message does not reuse the last key.
PBKDF2
The passphrase is hashed hundreds of thousands of times before it can unlock this device.
Double ratchet
Each message gets its own key. After the message is read, that key is thrown away. A recovery code on a new screen still cannot open messages that were already read.
01 · k7n4…read, then gone
02 · q9wm…read, then gone
03 · new keyonly this message
SENDING PAUSED
Key-change warning
If their key is no longer the one you started with, nothing else goes out. You compare the safety number first. That is how a swapped key gets caught.
Key history check
Their public keys are kept as a chain. Each new one has to follow the last. If the chain breaks, sending pauses, so a quiet swap is harder to hide.
a1 → b7 → c4c4 → ??
Lock now
● ● ● ●
Passphrase required
You do not have to wait for the timer. Lock the screen yourself and the passphrase is required again immediately.
Forget this device
k7np · private key
Deleted from this browser.
If you are done with this phone, the key does not stay behind.
Lock this browser
You pick a passphrase for this browser. It stays on the device and is never sent to the server.
On this device
● ● ● ●
On the server
never sent
You also get one recovery code, shown once. Write it down. It unlocks Blackout Chat on a new browser or a new app screen.
Set a handle
This is the name people search to find you. Yours might look like this.
Night shift
@nightshift
Then open a thread, seal it, and let it burn if you want.
Ready when you are.
Blackout Chat is free, because you have a right to privacy. Blackout Chat itself cannot read the messages, and they are not used to train AI. A new browser does not receive old messages.
Get Blackout Chat