International Morse Code

What Is International Morse Code?

International Morse code (also called Continental Morse) is the ITU-standard mapping of Latin letters, digits, and common punctuation to short signals (dots / dits) and long signals (dashes / dahs). It is the code used in amateur radio, aviation and maritime backup signalling, training apps, and almost every modern Morse converter worldwide.

When people search for “International Morse,” they usually want the official letter table — not a historical US wire code, and not a dialect of slang. This page gives you the live ProSignal tool plus complete static reference tables for A–Z, 0–9, and punctuation.

International Morse vs American Morse

American Morse (Railroad Morse) was used on 19th-century landline telegraph circuits in North America. Some letters use different patterns, and spacing rules differ from radio practice. It is historical and obsolete for modern on-air use.

International Morse was standardised for wireless and later formalised under ITU recommendations. Every chart, audio sample, and conversion on this site uses International Morse only — the same set you will hear in CW practice and licence courses.

If a printed chart from an old book disagrees with the tables below, check whether it is labelled American Morse. For radio, learning apps, and this translator, always use International.

Quick History

Samuel Morse and Alfred Vail developed early American telegraph codes in the 1830s–40s. Continental / International Morse evolved for European landlines and wireless, then became the worldwide radio standard. ITU recommendations now define the timing and character set used here.

International Morse Letters A–Z

Complete ITU letter set. Memorise by sound when you can — use Play signal above after typing a letter or short word.

For an interactive click-to-hear grid focused on the alphabet alone, open the Morse code alphabet chart.

International Morse Numbers 0–9

Each digit is exactly five symbols — a reliable pattern family once you know the “ramp” from 1 to 0.

More number-focused practice and calculators live on the Morse numbers page when you need digits alone.

International Morse Punctuation

Common punctuation marks in the International set. Unsupported characters are skipped by the converter rather than guessed.

International Morse Timing Standards

ITU timing is part of the standard. Wrong gaps make correct symbols unreadable.

• Dot (dit) = 1 time unit
• Dash (dah) = 3 units (1:3 ratio)
• Gap inside a letter = 1 unit
• Gap between letters = 3 units
• Gap between words = 7 units

WPM sets how long one unit lasts. Farnsworth practice keeps character speed higher while stretching letter/word gaps — details on Morse code timing.

Amateur operators also use short text abbreviations (73, CQ, QTH) — see Morse abbreviations — and continuous procedural signals on the prosigns page.

In written Morse on this site, letter gaps appear as spaces and word gaps as /. The WPM slider scales unit length when you play audio or flash the lamp.