Sidetone
Learn Morse code — by ear and on the key
About the app
Sidetone is a Morse code (CW) trainer for radio amateurs and enthusiasts. It teaches you to copy Morse by ear and to send it on a key, using the proven Koch method — starting at full target speed with a couple of characters and adding more as you get them right. It runs locally on your device, needs no account, and works offline.
Practice modes
- Copy training — receive by ear with the Koch method; type what you hear as the character set grows
- Send training — key characters on a straight key or iambic paddle and get scored on your sending
- Learn characters — meet each character one at a time, with its rhythm and sound
- Free keyer — a free-practice keyer with a real sidetone and no scoring
Built for real practice
- Koch method with a rolling, accuracy-based unlock of new characters
- Adjustable character and Farnsworth (effective) speed
- Practice statistics and a daily practice goal
- Local-first — no account required, works offline
- Privacy-friendly — no tracking, no ads
On the horizon
Sidetone is growing. Planned additions include a community for practising QSO procedures together, decoders for real off-air signals, and a Bluetooth Morse key interface so you can practise sending on real hardware.
Available on
Get the app
Coming soon to the App Store and Google Play.
Support & legal
Questions or feedback? Email hello@wissmueller.net.