Morse Code Translator

The international standard

The code here is International Morse code as defined by the International Telecommunication Union in Recommendation ITU-R M.1677-1: the 26 letters, the accented É, the ten digits, and the punctuation the recommendation lists — full stop, comma, colon, question mark, apostrophe, hyphen, slash, brackets, quotation marks, the double hyphen (=), the plus sign and @. The @ sign, .--.-., is the most recent addition, made in 2004.

Morse has no lowercase, so text is sent as capitals and read back as capitals. Some marks in everyday use — the exclamation mark, the ampersand, the semicolon, the underscore and the dollar sign — are not in the ITU recommendation; they are sent here with their widely used unofficial codes and flagged whenever you use them. Accented letters other than É have no international code, so ñ is sent as N and ü as U, and the tool tells you when it has done so. Anything else with no Morse equivalent, such as # or an emoji, is left out and listed.

Timing: dots, dashes and the PARIS standard

Morse is defined by rhythm, not by sound. The basic unit is the length of a dot. A dash lasts three dots; the silence between the dots and dashes of one letter lasts one; between letters, three; between words, seven. Every timing in the tool follows those ratios.

Speed is measured in words per minute, and a word is defined as PARIS followed by a word gap — exactly 50 units. At W words per minute a dot therefore lasts 1,200 ÷ W milliseconds: 60 ms at 20 wpm, 240 ms at 5 wpm. The line under the player shows the exact values for the speed you have chosen. A second reference word, CODEX, is 60 units long and gives a slower rate for the same setting; PARIS is the one almost everyone uses.

Around 20 wpm is a comfortable speed for experienced operators, and beginners usually start between 5 and 13. Amateur radio licence exams were once commonly set at 5, 13 or 20 wpm, but most countries dropped the Morse requirement after the ITU stopped mandating it in 2003.

Farnsworth spacing for learners

Someone who learns at 5 wpm learns to count dots and dashes, and later has to unlearn it, because at real speeds letters are heard as whole rhythms rather than counted. Farnsworth spacing, named after Donald “Russ” Farnsworth, W6TTB, solves that by sending each letter at a higher character speed — typically 15 to 20 wpm — while stretching the gaps between letters and words so the overall rate stays slow enough to follow.

Turn it on and choose the overall speed you can manage. The dots, dashes and the gaps inside letters stay at your character speed; only the gaps between letters and words are stretched, using the formula in the ARRL's Farnsworth timing standard, so that the word PARIS takes exactly as long as your overall speed implies. As you improve, raise the overall speed towards the character speed until the extra spacing disappears.

SOS and the other prosigns

SOS is not an abbreviation — not “save our souls”, not anything. It was chosen because its pattern of three dots, three dashes and three dots is unmistakable, and it is sent as one continuous signal with no gaps between the letters. It was adopted at the international Radiotelegraph Convention in Berlin in 1906 and came into force in 1908. Type SOS and you get three separate letters, ... --- ...; type <SOS>, in angle brackets, and you get the distress signal itself, ...---..., with no gaps at all.

Other procedural signs work the same way: <AR> for end of message, <SK> for end of contact, <BT> for a break, <KN> to hand over to one named station, <AS> for wait. Several share a code with a punctuation mark — <AR> is the same as +, and <BT> the same as = — so when you decode, they come back as those characters. The alphabet chart under the player lists every code and prosign.

Morse is far from dead. Radio beacons and aviation navigation aids still identify themselves with a few letters of it, amateur radio operators use it daily because it gets through when voice cannot, and it is an accessibility tool: phone keyboards offer Morse input for people who can press one or two switches but cannot use a touchscreen.

Sound, lamp and WAV file

Playback uses your browser's Web Audio engine. Each tone has a few milliseconds of soft rise and fall, the way a well-adjusted transmitter shapes its signal, because a tone that starts and stops instantly produces audible clicks. Choose a pitch between 300 and 1,000 Hz; many operators settle somewhere between 500 and 800 Hz, which stays comfortable over a long session.

The lamp flashes from the audio clock, so it matches what you hear. If your device is set to reduce motion, or you untick Flash the lamp, it stays lit while sending instead of flashing, and the letter being sent is shown beside it either way. The lamp is kept small — well under the size at which the Web Content Accessibility Guidelines treat rapid flashing as a seizure risk.

Download WAV writes the same sound to a file: uncompressed 16-bit mono audio at 22,050 samples per second, about 2.6 MB a minute, which plays in any media player and opens in any audio editor. Audio is limited to ten minutes per message. One honest limit: this tool does not listen, so it cannot decode Morse from a recording or a microphone.