decode FSK modem audio from a file or your microphone
A note on mic decode. FSK demodulation over an acoustic path (speaker → air → mic) is inherently lossy. Background noise, microphone frequency response, speaker quality, room reverb, and browser audio processing all distort the signal. You may see garbled output, extra characters, or nothing at all — especially at higher baud rates. For reliable results, use DECODE FILE with a WAV directly. Mic decode works best in a quiet room with the source close to the mic.
HOW TO USE
Select a protocol, click START LISTENING, then play modem audio through your speakers or hold your device near the source. The decoder will pick up FSK tones through your microphone and convert them to text in real-time.
Try it: encode some text on the main page, download the WAV, then play it back while this page listens.