Ditdah

Morse code is not dots and dashes. It is rhythm — strict proportions of sound and silence, where a dah lasts exactly three dits and the gap between words lasts seven. Ditdah is built around that fact, and it gets the timing right.

Type a message and send it as sound, vibration, torch flashes or a flashing screen. Watch the signal scroll past as a timeline while the character being transmitted lights up in your text. Tap out Morse yourself on a telegraph key that adapts to your tempo. Learn the code properly with the Koch method. Everything runs on your device; there is no internet permission at all.

⚙️ HOW IT SENDS
• Sound — a clean sidetone with smoothed edges, so there are no clicks on every element
• Vibration — the message keyed through the motor as one prepared waveform
• Torch — flashed through the camera light, timed against the hardware's real delay
• Screen — the whole display as a signal lamp
• Play, pause, stop and loop, with a scrolling signal timeline

📻 THE TIMING
• PARIS standard: one unit = 1200 / WPM, adjustable from 5 to 40 WPM
• True proportions throughout: 1 / 3 / 1 / 3 / 7
• Farnsworth timing — characters stay fast while the gaps stretch, which is how you learn to hear a letter as one sound instead of counting elements

🔤 THE CODE
• Letters, digits and punctuation: . , ? ' ! / ( ) & : ; = + - _ " $ @
• Prosigns in brackets — ‹SOS› ‹AR› ‹SK› ‹BT› ‹KN› ‹AS› ‹HH› — sent run together, as they should be
• Morse in, text out: dots and dashes, "dot dash" words, or ·− symbols
• Anything that cannot be sent is pointed out, never silently dropped

🎛️ THE KEY
• Hold for a dah, tap for a dit; your pauses mark the letters and words
• Adapts to your actual speed, or holds a speed you set
• Tone and vibration under your finger

🎓 LEARNING
• The full code chart, searchable, tap any row to hear it
• Koch method: two characters at full speed, one more each time you reach 90%. Speed never goes up — recognition does
• A quiz that drills whatever you keep getting wrong
• Sending practice, scored on accuracy and on rhythm

🎤 LISTENING (EXPERIMENTAL)
• Point the phone at a Morse tone and it decodes what it hears
• Finds the sender's tone by itself and shows a confidence bar
• Honest about its limits: good on a clean tone in a quiet room, unreliable on hand-sent code, defeated by speech or music. It says when it cannot hear a signal rather than inventing text

🗂️ AND
• History of what you sent, tap to bring it back
• Favourite phrases, and WAV export of any message
• Light and dark themes, amber or green phosphor

⚠️ IMPORTANT
Ditdah flashes the torch and the screen. Flashing light can trigger seizures in people with photosensitive epilepsy, including people who have never had one. The app refuses light output above 15 WPM for exactly this reason, and asks before the first use.

Ditdah is a hobby and learning tool. Please do not rely on it as a means of emergency signalling or communication.

No accounts, no ads, no analytics, no network access. Your messages stay on your phone.