RTTY Decoder - Radio to Text

Read radio signal tones as text with RTTY Decoder. RTTY (Radio Teletype) is a way to send text over radio. This app decodes ITA2/Baudot RTTY audio from your microphone or local recordings.

Built for ham radio operators and shortwave listeners, this RTTY decoder helps you inspect audio from an external receiver, revisit recordings and practice tuning with generated test audio.

Features
• Live RTTY decoding: Analyze receiver audio through your microphone.
• Audio file decoding: Open audio files supported by your device and read the decoded text.
• Waterfall and spectrum: Inspect signals visually and adjust Mark and Space frequencies.
• Tuning controls: Use Auto Tune, automatic frequency control (AFC), manual tuning and reverse polarity to match your signal.
• RTTY presets: Start with 45.45 baud / 170 Hz and adjust baud rate, frequency shift and framing.
• History and export: Copy decoded text, reopen saved sessions and share TXT files. Export multiple sessions as CSV or ZIP.
• RTTY audio generator: Turn text into test audio, play it back, and save or share a WAV file.
• On-device processing: Audio decoding runs locally on your device.
• English and Korean interfaces with light and dark themes.

For listening and practice
Check RTTY audio from your radio receiver, analyze saved recordings or generate test signals to practice Baudot decoding. Save custom presets to reuse your preferred settings.

Before you start
This app does not receive RF signals directly. Live radio decoding requires a separate receiver and an audio input. File compatibility depends on the audio formats supported by your Android device. Results vary with signal quality, noise and decoder settings.

The app contains ads, which may use an internet connection.

Use RTTY Decoder to turn received audio into text you can review and keep.