Say it without saying it.
Zwisper hides an encrypted note inside a message you were already going to send. Everyone sees the normal words. The person it is for sees the note, and it opens by itself on their side.
Free. No account. Nothing leaves your device.Three steps, no new app
It runs on top of the chat and mail you already have open. Nobody has to join anything.
Write
Type your message the way you always do. Add the note and pick who it is for: a contact, or a one-time password.
Send
Paste it anywhere. To everyone else it is the same sentence, letter for letter. The note rides inside as invisible characters.
Read
Your contact's Zwisper spots the note and opens it, marked verified. Anyone else needs the password you gave them.
Works where you already talk
Click into any text box in Chrome and the Hidden note pill appears. Notes that arrive get a purple underline.
In Chrome, click into any text box and the Hidden note pill appears.
On your phone? Same thing, no install.
Extensions do not run on phones, so the web app covers the rest. Write and read notes in any browser, keep your contacts there, and add it to your home screen. It is copy and paste: nothing opens inside other apps by itself.
Privacy, plainly
There is no one behind it to trust or distrust. Here is what that means in practice.
No server
Zwisper makes no network requests of its own. There is nothing for us to log, because nothing reaches us.
No account
Your contacts are encrypted on your own device under a passphrase you choose. Nobody can reset it, including us.
Open format
AES-256-GCM, Argon2id and Ed25519 signatures. When both people have Zwisper, a back-and-forth becomes a forward-secret conversation.
Honest limits
Zwisper is private, not invisible to someone looking hard. A screenshot of a message loses the note inside it. Some platforms strip invisible characters when you send, so Zwisper checks the box before you do and tells you. And a platform can see that a message carries invisible characters, even though it cannot read them. Zwisper is for keeping a note between two people in an ordinary conversation, not for hiding from someone who is actively looking.
