Audio Watermark
A free steganography tool that hides ownership text inside audio files using ultrasonic spread-spectrum encoding. The hidden signature survives MP3 compression, format conversion, and most audio edits — without any audible change to your recording.
Stamp your recordings with an inaudible copyright signature — invisible, tamper-resistant, browser-only
Features
FAQ
Can people hear the watermark?
No. The watermark is encoded at an 18.5 kHz ultrasonic carrier using spread-spectrum modulation. At Normal strength it is completely imperceptible on any standard playback system.
Does it survive MP3 compression?
Yes at Normal and Strong settings. MP3 encoding removes some high-frequency energy, but the spread-spectrum signal is distributed broadly enough to survive typical 128–320 kbps compression. Light watermarks may weaken after aggressive compression.
Is this processed on a server?
No. All encoding and detection runs entirely inside your browser using the Web Audio API. Your audio file never leaves your device.
What languages and scripts are supported?
Any text encoded as Unicode UTF-8 works: Latin, Cyrillic, Arabic, Chinese, Japanese, Korean, and all other scripts. Emoji are supported too.
What is metadata embedding?
Checking "Also embed in file metadata" writes the watermark text into the audio file's ID3 or Vorbis comment tags. This provides a second, easily readable layer of ownership information alongside the hidden steganographic signature.
Can I use the watermark to prove ownership in court?
A steganographic watermark can serve as supporting evidence of authorship — especially when combined with metadata embedding and a dated original file. However, it is not a legal certificate by itself. For formal copyright registration consult the relevant authority in your country.
