Morse code translator

How Morse code works

Morse code spells out text with two signals: a short one, the dot (also called a dit), and a long one, the dash (or dah). The International Morse code, set out by the International Telecommunication Union in Recommendation ITU-R M.1677-1, fixes the rhythm in four rules:

• a dash lasts as long as three dots;
• the gap between the dots and dashes of one letter is one dot;
• the gap between letters is three dots;
• the gap between words is seven dots.

Written down, letters are separated by spaces and words by a slash, so "Hello world" becomes .... . .-.. .-.. --- / .-- --- .-. .-.. -.. in Morse.

Speed is measured in words per minute (WPM), and since words vary in length, the standard word is "PARIS" (.--. .- .-. .. ...), which is exactly 50 dot-lengths long including the gap after it. So a dot lasts 1,200 ÷ WPM milliseconds. At 20 WPM that is 60 ms, a dash is 180 ms, a letter gap 180 ms and a word gap 420 ms.

A short history

Samuel Morse and his partner Alfred Vail developed the code for Morse's electric telegraph. On May 24, 1844, Morse sent the first message over a line from the US Capitol in Washington to Vail in Baltimore: "What hath God wrought?" That original code, now called American Morse, had gaps inside some letters (C, O, R, Y and Z) and extra-long dashes for L and zero. It stayed in use on American landline telegraphs and railroads for about a century.

In 1848 the German telegraph engineer Friedrich Gerke simplified it, with no gaps inside letters and one length of dash. His version became the basis of the International Morse code, which the International Telegraph Union, founded in Paris in 1865, made the standard for telegraphy between countries. It is the code used on radio, in amateur radio and by this translator. It still changes now and then: the @ sign (·−−·−·) was added in 2004 so operators could send email addresses.

SOS and other prosigns

Some signals are sent as one character made of several letters run together, with no gap between them. They are called prosigns and written with a bar over the letters, or between angle brackets here. The best known is SOS, ...---..., the distress signal adopted at the Berlin radiotelegraph conference of 1906. Others include AR (.-.-., end of message, the same signal as +), K (-.-, over to you), BT (-...-, new section) and SK (...-.-, end of work). Type <SOS> or <AR> in the translator to send one.

Learning Morse code

Learn each letter as a sound, not as a picture of dots and dashes: experienced operators hear "di-dah" and think A without counting. Two methods help. The Koch method, from the German psychologist Ludwig Koch in the 1930s, starts with just two letters at full speed and adds a new one each time you copy about 90% correctly. Farnsworth timing sends each letter at a fast speed but stretches the gaps between letters and words, so the rhythm of each letter stays the same while you get time to think. In 1990 the ARRL, the US amateur radio association, published a standard for it: below 18 WPM, its practice code keeps the letters at 18 WPM and adds the extra time to the gaps. For example, 18 WPM letters at 10 WPM overall stretch the letter gap from 200 ms to 621 ms and the word gap to 1,449 ms.

Turn on Farnsworth spacing above, choose a few letters from the chart and practice a little every day. For other conversions, the binary translator turns text into the ones and zeros computers use, and number to words spells out numbers. To count the characters in a message first, use the character counter.

International Morse code chart

Every character in ITU-R M.1677-1. The chart in the tool also lists the prosigns and plays each sign.