International morse, not “American” morse
Two morse variants exist. Original American Morse (or “Railroad” morse) used variable-length internal spaces and survived in US railroad telegraphy into the 1970s. Almost nothing uses it today. International Morse — standardised in 1865 at the International Telegraph Conference in Paris — uses only short and long pulses with fixed gaps, and is the one we convert to.
Every letter A–Z, digit 0–9, and the full punctuation set (period, comma, question mark, exclamation mark, apostrophe, quotation mark, parentheses, colon, semicolon, hyphen, ampersand, at-sign, dollar-sign, plus-sign, equals-sign, forward-slash, and underscore) is in our table.
How the converter handles edge cases
- Mixed case: morse has no uppercase-vs-lowercase distinction. The converter normalizes everything to uppercase before encoding.
- Numbers: each digit is a fixed five-element code (e.g.
3 = ...--). Great rhythm for drilling at speed. - Punctuation: commas and periods are common and well-supported. More exotic marks (emoji, CJK, diacritics) aren't in ITU morse and get silently dropped rather than producing a
?. - Spaces and paragraphs: single spaces become the word separator
/. Multiple consecutive spaces and line breaks collapse to a single/— morse has no concept of a paragraph break.
Common conversions
HELLO→.... . .-.. .-.. ---73(ham radio for “best regards”) →--... ...--CQ(calling any station) →-.-. --.-I LOVE YOU→.. / .-.. --- ...- . / -.-- --- ..-
Why English is unusually efficient in morse
Morse was built around English letter frequencies, and converting English is where that design pays off. The letters that appear most often — E (one dot) and T (one dash) — got the shortest codes, so a typical English sentence encodes into far fewer dots and dashes than its letter count suggests. A word like the, three of the commonest letters in the language, is just - .... . — six elements. The same isn't true for every language: encode a word full of rare letters and the morse balloons. English, the language the code was tuned for, is close to a best case.
English quirks that surprise people
A few things about English catch people out in the output. Morse encodes spelling, not sound, so silent letters are still sent in full — knight keeps its K and its GH (-.- -. .. --. .... -), and hour keeps its silent H. Homophones that sound identical look completely different: their, there and they'reeach produce their own distinct pattern. And English's two one-letter words are the shortest possible messages — I is .. and a is .-, each a single character you could flash in under a second.