Hide Secret Messages in Audio Files
Using ultrasonic frequencies. Free, private, no sign-up.
Drop a .wav file here or click to browse
How It Works
1. Type Your Message
Enter up to 140 characters of secret text. Optionally record a voice to camouflage the signal.
2. Encode into Audio
Your message is converted into ultrasonic frequencies — completely inaudible to human ears.
3. Download & Share
Download the WAV file and share it. Only people with this tool can decode the hidden message.
Features
Inaudible
Ultrasonic frequencies above 18 kHz. Humans can't hear it, but microphones can decode it.
Browser-Based
No installation required. Works in any modern browser with Web Audio API and WebAssembly support.
Privacy First
Everything runs locally in your browser. Your files and messages never leave your device.
Voice Camouflage
Record your voice to mask the signal. The message hides inside a normal-sounding audio clip.
Live Detection
Open a microphone and detect hidden messages in real-time from any audio source nearby.
100% Free
No sign-up, no limits, no watermarks. Use it as much as you want, forever.
Use Cases
Covert Communication
Exchange secret messages embedded in innocent-sounding audio files. The message is completely invisible to anyone who doesn't know it's there.
Audio Watermarking
Embed invisible identifiers in audio content to track unauthorized distribution or prove ownership of recordings.
CTF Challenges
Create Capture The Flag challenges using audio steganography. Hide flags in WAV files for competitors to discover and decode.
Education & Research
Learn about audio steganography, digital signal processing, and information security through hands-on experimentation.
Frequently Asked Questions
Can people hear the hidden message?
No. By default, HideInAudio uses ultrasonic frequencies (above 18 kHz) that are inaudible to the human ear. The audio file sounds completely normal. If you choose an audible protocol, the encoding will be hearable as a series of tones.
Is my data private?
Yes. All processing happens entirely in your browser using WebAssembly. Your audio files and messages never leave your device. Nothing is uploaded to any server.
What audio formats are supported?
HideInAudio works with WAV files (48 kHz, 16-bit, mono). When you record voice directly in the browser, it is automatically converted to this format.
How long can my message be?
Messages can be up to 140 bytes (roughly 140 ASCII characters). This is a limitation of the underlying ggwave acoustic data transmission protocol.
Does compression (MP3, AAC) destroy the hidden message?
Yes, lossy compression removes the ultrasonic frequencies that carry the hidden message. Always share the original WAV file for reliable decoding.
What is the "Live Listen" feature?
Live Listen opens your microphone and decodes hidden messages from any audio playing nearby in real-time. Point your device's mic at a speaker playing a HideInAudio-encoded file to reveal the message.
What technology powers this?
HideInAudio uses ggwave, an open-source library for acoustic data transmission by Georgi Gerganov. It encodes data into sound using frequency-shift keying (FSK). The WASM version runs entirely in your browser.