Blank: Hide in Sound

Blank hides private messages inside ordinary-sounding audio. Pick a sound, type a secret, set a password, and Blank gives you back a normal audio file with your message woven invisibly inside. Anyone can play it. Only someone with the password can reveal what is hidden.

Everything happens on your device. Your messages and passwords never leave your iPhone.

HOW IT WORKS
• Encrypt: your message is sealed with AES-256 using your password.
• Hide: the encrypted data is woven into the audio, inaudibly.
• Reveal: open a Blank file, enter the password, read the message.

FEATURES
• Hide encrypted text inside 16-bit WAV audio
• Seven built-in cover sounds (rain, waves, wind, stream, campfire, night, soft static), or import your own
• On-device only. Nothing is ever uploaded.
• A wrong password or an altered file is detected, never faked
• Face ID app lock
• Light and dark, clean and modern
• Preview the audio in the app before you share

SHARING IT SAFELY
For AirDrop, Files, or email, share the audio file. To send it through a chat app like WhatsApp or Telegram, tap Send safely, which delivers the file without re-compressing it. A voice note or re-compressed audio erases the hidden message.

BLANK PRO
A one-time purchase unlocks unlimited message length. The free version hides short messages.

Blank is a privacy and education tool built around classic audio steganography and modern encryption.