Reference · ITU-R M.1677-1
The Morse code alphabet
The Morse code alphabet gives every letter, digit and punctuation mark a fixed pattern of dots and dashes. International Morse code, defined in ITU-R M.1677-1, has 26 letters between one and four elements long, 10 digits of exactly five elements, and 13 punctuation marks. Press any character below to hear it at your chosen speed.
- Letters
- 26
- Digits
- 10
- Marks
- 13
Morse code letters A–Z
Morse code numbers 0–9
Punctuation in ITU-R M.1677-1
The standard defines 13 punctuation marks. It also has a multiplication sign, which is sent exactly like the letter X (−··−), so it is not listed separately here.
Common but not in ITU-R M.1677-1
These five marks are widely used and every MorseForge tool accepts them, but ITU-R M.1677-1 does not define them, so a receiver may not know them.
Why the codes are what they are
The alphabet is not arbitrary. Morse is a prefix tree: from a starting point, a dot branches one way and a dash the other, and every character sits where its own sequence lands. E is one dot because E is the most common letter in English, and the shortest codes went to the letters that would be sent most often.
The digits give this away most clearly. 1 is one dot and four dashes, 2 is two dots and three dashes, and so on until 5 is five dots. Then the pattern turns around: 6 is one dash and four dots, and so on until 0 is five dashes. It is a rule you can derive rather than a table you have to memorise.
Common questions
- How many characters are in the Morse code alphabet?
- International Morse code, as defined in ITU-R M.1677-1, has 26 letters, 10 digits and 13 punctuation marks. This chart also includes 5 widely used marks that the standard does not define: the exclamation mark, ampersand, semicolon, underscore and dollar sign. Letters are one to four elements long and every digit is exactly five.
- Why is E just one dot?
- Because E is the most common letter in English. Morse assigned the shortest codes to the most frequent letters, which is a form of frequency encoding — the same principle behind modern compression. Q and Z are long precisely because they are rare.
- What is the easiest way to remember Morse code numbers?
- Count the dots. 1 is one dot and four dashes, 2 is two dots and three dashes, and so on up to 5, which is five dots. From 6 the pattern reverses: 6 is one dash and four dots, up to 0, which is five dashes. Every digit is exactly five elements long.
- Which letters are the longest in Morse code?
- No letter is longer than four elements, and 12 letters share that length: B, C, F, H, J, L, P, Q, V, X, Y and Z. H is the only letter made of four dots, and no letter is made of four dashes.
- How long is a dot and a dash in Morse code?
- A dot, or dit, lasts one unit and a dash, or dah, lasts three. The gap inside a character is one unit, between letters three units and between words seven. At 20 words per minute one unit is 60 milliseconds, so a dash lasts 180 milliseconds.
- Is there a Morse code for lowercase letters?
- No. Morse has no case at all. It also has no way to indicate a paragraph or a new line beyond the prosign BT. Anything sent in Morse arrives as uppercase by convention, not because it was sent that way.
- What is the difference between American and International Morse?
- American Morse, the original, used variable-length internal gaps inside some characters. Those gaps were readable on a landline sounder but not over radio, where fading and interference blur them. International Morse replaced it worldwide and is what every modern reference means by "Morse code".