Morse Code Translator.

What Is International Morse Code?

International Morse code is the standardized system of dots and dashes used around the world to send letters, numbers, and punctuation as sound, light, or on/off pulses. It is the version you get when most people say "Morse code" today, and it is the one used in amateur radio, aviation, and maritime signaling. It is maintained as a formal standard by the International Telecommunication Union (ITU) in recommendation ITU-R M.1677-1.

Tip: press ▶ on any row in the chart below to hear that character.

What makes it "international"

The word "international" is there to separate this code from the older American Morse code that ran on United States telegraph lines in the 1800s. American Morse used internal pauses inside some letters and dashes of different lengths, which worked fine for a skilled operator sitting at a wire but fell apart over long undersea cables and, later, over radio.

International Morse code fixed that. Every character is built from just two lengths, a short signal (the dot, also called a dit) and a long signal (the dash, also called a dah), with no odd internal gaps. That consistency is the whole point. It made the code easy to teach, easy to send by radio, and readable no matter which country the operator learned it in. You can see the full set on the Morse code chart.

How the timing works

International Morse code is defined entirely by timing, and the rules are simple once you see them as multiples of one basic unit:

  • A dot is one unit long.
  • A dash is three units long.
  • The gap between dots and dashes inside a single letter is one unit.
  • The gap between letters is three units.
  • The gap between words is seven units.

That is the entire timing system. Because the meaning lives in the rhythm rather than in any specific tone or color, the same code travels as beeps on a radio, flashes from a signal lamp, clicks down a wire, or audio you can play and decode. Speed is measured in words per minute, and the standard word used for the measurement is "PARIS," which happens to be exactly 50 units long.

The full alphabet at a glance

Letters:

A .- B -... C -.-. D -.. E . F ..-. G --. H .... I .. J .--- K -.- L .-.. M -- N -. O --- P .--. Q --.- R .-. S ... T - U ..- V ...- W .-- X -..- Y -.-- Z --..

Numbers:

0 ----- 1 .---- 2 ..--- 3 ...-- 4 ....- 5 ..... 6 -.... 7 --... 8 ---.. 9 ----.

The letters were not assigned at random. The most common letters in English got the shortest codes, so E is a single dot and T is a single dash. For the full reference including punctuation and prosigns, see the Morse code chart and the alphabet page.

Where it came from

International Morse code grew out of a revision made by a German telegraph inspector named Friedrich Clemens Gerke in 1848. Gerke stripped out the irregular parts of the original Morse and Vail code and left the clean two-length system we use now. Continental European telegraph networks adopted his version through the 1850s, and the International Telegraph Union (the body that became today's ITU) formalized it as the international standard in 1865. It has barely changed since a small punctuation update in 1938. For the fuller story of how the code started, see who invented Morse code.

Where it is used today

International Morse code is no longer required for commercial or maritime licensing, but it is far from a museum piece. Amateur radio operators still use it every day because a Morse signal, known on the air as CW, punches through noise and weak-signal conditions that would swallow a voice transmission. Aviation uses it to identify navigation beacons, where a pilot can confirm a VOR or NDB station by its two or three letter Morse identifier. It also serves as an accessibility tool, and it remains the go-to emergency signal through SOS.

If you spend any time in the amateur radio community on Reddit, in subreddits like r/amateurradio and r/morse, you will see the same friendly argument on repeat: people are often surprised that Morse is still active in 2026, and longtime operators point out that a cheap low-power radio and a straight key can cross oceans when nothing else will. That staying power is a big part of why the international standard has outlived almost every technology that replaced it.

International Morse code vs American Morse code

The short version is that International Morse code won and American Morse code faded out. American Morse was slightly faster in skilled hands but harder to send cleanly over cables and radio, so the world standardized on the international version. Several letters are genuinely different between the two, including C, L, O, R, Y, and Z, and the number zero. For a full side-by-side breakdown, see International vs American Morse code.

Frequently asked questions

Is Morse code international? The version used worldwide today is International Morse code, standardized by the ITU. An older American Morse code existed but is now used only by a small group of hobbyists and historians.

What is the difference between Morse code and International Morse code? When people say "Morse code" now, they almost always mean International Morse code. The name is used to distinguish it from the original American Morse code that had different patterns for some letters.

Is International Morse code the same as Continental Morse code? Yes. "Continental Morse" is an older name for the same code, from the days when it was the standard on the European continent.

Who standardized International Morse code? It is based on Friedrich Gerke's 1848 revision and was adopted as an international standard in 1865. The ITU maintains it today in recommendation ITU-R M.1677-1.

Sources

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