Letters · ITU International Morse Code
Morse code for O is --- — 3 signals (0 dots, 3 dashes). NATO: Oscar.
The letter O is forms the other half of SOS (−−−). In international Morse code it is ---: long press, then long press, then long press.
Whether you're learning for ham radio, aviation, survival, or personal interest — this page covers audio playback, visual display, timing guide, memory tip, and an interactive practice quiz.
Select the correct Morse code for O:
To transmit Letter O (---), use this sequence:
| Speed | Dot | Dash | Letter gap | Word gap |
|---|---|---|---|---|
| 5 wpm | 240ms | 720ms | 720ms | 1680ms |
| 10 wpm | 120ms | 360ms | 360ms | 840ms |
| 20 wpm | 60ms | 180ms | 180ms | 420ms |
O is round and long — three dashes: − − −
The Morse code for Letter O is --- — 0 dots and 3 dashes. Transmitted as: long press, then long press, then long press.
To write Letter O in Morse code use ---. A dot is a short signal and a dash is 3 times longer.
To tap Letter O: long press, then long press, then long press. Follow ITU timing: dot=1 unit, dash=3 units, gap between signals=1 unit, gap between letters=3 units.
In international Morse code, --- stands for the letter O (NATO: Oscar). This is part of the ITU standard alphabet.
Most learners memorize Letter O (---) within minutes. Practice tip: O is round and long — three dashes: − − −.
Characters with similar Morse patterns: