CW Decoder

You can use the core feature—Morse code decoding—free of charge with no time limit. [Premium] Continuous decoding: 3-minute sessions (restart anytime). Font settings.

High-Precision Morse Code Decoder

Achieve noise-resistant, accurate Morse code decoding with high-precision, sample-level signal processing. Try the superior “listening performance” in the free version.

Differences Between Free and Full Versions This app lets everyone try the high-performance decoding engine for free.

Free Version

• Continuous decoding: Up to 3 minutes per session (restart anytime, unlimited times)
• Basic font display Ideal for testing performance and checking short communications.

Full Version (Paid Add-on)

• Unlimited time: For long ragchews and continuous monitoring
• Font settings: Customize font type and size for better visibility Recommended for active operation and a stress-free learning experience.

Main Features & Technology

High-Precision Real-Time Decoding

• Speed range: 5–50 WPM (auto-adjust speed and threshold)
• Frequency detection: 400–900 Hz (automatically tracks the strongest signal)

Advanced Signal Processing

• Bandpass filter: Narrowband filtering reduces unwanted noise
• AGC (Automatic Gain Control): Compensates for signal level changes and fading
• Noise blanker: Reduces spike noise using MAD (Median Absolute Deviation)
• Signal stabilization: Multi-sample buffering helps prevent false detections

Designed for Real-World Use

• Scrollable text: Review and check missed content
• Frequency lock: Tracks the actual operating frequency range (400–900 Hz)
• Visual support: On-screen text supports listening and copying

Recommended For

Morse Code Beginners Great for those getting started with Morse code. Seeing decoded text while listening helps self-correction and improves learning efficiency.

Amateur Radio Operators

• CW practice: Compare results with your own copying to find weak points
• Contests: Helpful for high-speed reception support and log checking
• Portable ops: No PC needed—build a CW reception setup with just a smartphone

Comeback Hams & Experts Useful for reducing fatigue during long monitoring sessions and supporting operators with hearing decline. Powerful filtering helps decoding in weak-signal or interference conditions.

Note: Microphone permission is used only for signal analysis. No audio is saved or transmitted.