International Morse, ITU-R M.1677
Morse Code Reference
A timing based code of dots and dashes that encodes letters, digits, and punctuation over any channel that can switch on and off.
At a glance
Key factsStandard
Symbols
Dot, dash, and timed silence
Dash length
Three dot units
Word gap
Seven dot units
Where it comes from
Morse code grew out of the electric telegraph of the 1830s and 1840s and was refined into the International Morse code standardized by the ITU. Because it needs only a single on and off channel, it works over wires, radio, light, or a tapping finger, which is why it outlived the telegraph itself and is still used in aviation beacons and amateur radio.
How to use it
The code uses two symbols and the silences between them. A dot is one time unit and a dash is three. Symbols within a letter are separated by one unit, letters by three, and words by seven. Most operators learn by ear rather than by counting symbols, because the rhythm of a whole letter is easier to recognize than its individual parts.
This page is a standing summary. For the interactive tool and the full tables, open the morse code page. The data here is compiled from International Morse Code, standardized by the ITU (Recommendation ITU-R M.1677).