International Morse Code Chart

What "International Morse code" means

The chart above is International Morse code, the version standardized by the International Telecommunication Union in Recommendation ITU-R M.1677 and used worldwide in radio, aviation and maritime signaling. It descends from the code Friedrich Clemens Gerke devised in 1848 for German telegraph lines, which removed the awkward internal spaces and extra-long dashes of the original code and was adopted as the "Continental" standard in 1865.

The original 1844 code by Samuel Morse and Alfred Vail, now called American Morse code, survives only among telegraph historians and railroad enthusiasts. If you found a chart where C is .. . or O is . ., that is American Morse, not an error.

How to use the chart as a cheat sheet

1. Print it and keep it in sight. Tape it beside your screen or inside a notebook. Looking up a letter three times is enough to start remembering it.
2. Learn by groups, not alphabetically. Start with the one- and two-signal letters (E, T, I, A, N, M), then the three-signal letters, then the rest. The alphabet page presents them this way with audio.
3. Use the reverse table for decoding. When you are copying code, you hear a pattern and need the letter, which is the opposite direction from a normal chart. Count the signals and find the group.
4. Add the numbers last. They follow one rule (dots fill from the left for 1–5, dashes for 6–0) and take ten minutes once the letters are in place.
5. Retire the chart as soon as you can. A chart teaches you to see Morse; real fluency comes from hearing it. Use the practice quiz to wean yourself off the sheet.

Reading the chart: three things beginners miss

Spacing matters more than the symbols. .- is A, but . - with a letter gap is E followed by T. The same symbols with different spacing spell different things.

Prosigns are single characters. AR, SK and the rest are written with a bar over the letters because they are sent as one run of signals with no gap in between. ...---... sent as one character is SOS the distress signal; ... --- ... with gaps spells the same letters as an ordinary word.

Not every symbol is official. The exclamation mark, ampersand, semicolon, underscore and dollar sign are widely used conventions that are not in the ITU table. See the punctuation page for which marks are standard.