CW Decoder

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.