How do I translate Morse code from audio?

Drop the file on this Morse code audio translator or record it from the microphone. The page finds the tone, works out the length of a dot, sorts the tones and gaps by length and looks each letter up in the ITU table. You get the text, the dots and dashes, the tone and the speed.

Can it decode Morse code from a recording of a radio?

Sometimes. A strong single signal may read well. Noise close to the tone, fading deeper than about half, a second station on nearly the same pitch or uneven hand keying can all produce wrong letters. The timing score warns you when the lengths do not fit Morse, and you can type the tone and the speed yourself.

How fast is Morse code in words per minute?

It depends on the sender. Speed is counted on the word PARIS, 50 dots long with its word gap, so a dot lasts 1.2 ÷ WPM seconds: 60 ms at 20 WPM and 240 ms at 5 WPM. This page plays 5 to 40 WPM and reads speeds beyond that range with less certainty.

Does Morse code have letters like ä, ö, ü or ñ?

Not in the international standard. ITU-R M.1677-1 has the 26 letters and an accented e. German and Spanish operators have used added codes for Ä, Ö, Ü, ß and Ñ, so this page reads and writes those, going by German and Spanish Wikipedia. Another decoder may not.

Is my audio uploaded?

No. The file or microphone take is decoded and read by your browser, and the audio you make from text is built there too. Nothing is sent to a server, and it is gone when you close the page.

Morse Code Audio Translator

Decode Morse code from an audio file into text, or turn text into Morse code and play or save it as audio. It all runs in your browser. It works best on clean, machine-sent Morse with one steady tone.

Drop an audio file here or browse

MP3, M4A, AAC, WAV, OGG, OPUS, FLAC, WEBM or MP4, up to 100 MB and 30 minutes.

Everything runs in your browser. Your audio and your text are not uploaded.

How to translate Morse code from audio

1
Add the audio
Drop a file (100 MB and 30 minutes at most), or record from the microphone and stop when the message ends.
2
Read the result
The page finds the loudest steady tone, measures the speed, and shows the text, the dots and dashes, the tone in Hz and the speed in words per minute.
3
Correct it if needed
If the text looks wrong, type the tone or the speed you know and decode again. A poor timing score means the text should not be trusted.

Not sure of the tone? The peak is easy to see on the spectrogram, and the tone generator plays any pitch for comparison.

What decodes well, and what does not

This is a tone detector, not a trained listener. It looks for one steady pitch that switches on and off, then reads the lengths. Clean Morse sent by a computer or a keyer is the case it handles well.

The automated tests behind this page generate Morse at 400 to 1,000 Hz and read it back. Without noise the text came back exact at 5, 13, 20, 30 and 40 WPM. With white noise added, it stayed exact at 5, 13 and 20 WPM down to a signal-to-noise ratio of -10 dB, and at 30 WPM down to -5 dB. That ratio counts noise across the whole audio band; noise close to the tone hurts more. These are computer-made signals, so a real recording can do worse.

Hand-keyed Morse is harder. In the same tests, timing that varied by about 10% per element still read correctly at 13 and 20 WPM, some letters went wrong by 15%, and 30% was not readable. Two stations on nearly the same pitch defeat it, because it cannot tell them apart. A quieter station 200 Hz away is ignored. Very wide spacing between letters, known as Farnsworth timing, reads as extra word breaks.

One case has no answer in the timing: tones and gaps of equal length. TTTT looks the same as the letter H sent three times slower, and comes back as H. Type the speed to settle it.

Morse timing at common speeds

ITU-R M.1677-1 sets the proportions: a dash is three dots, with one dot between the signals of a letter, three between letters and seven between words. Speed in words per minute is counted on the word PARIS, which takes 50 dots with its word gap, so one dot lasts 1.2 ÷ WPM seconds.

WPM	Dot	Dash	Letter gap	Word gap
5	240 ms	720 ms	720 ms	1,680 ms
13	92 ms	277 ms	277 ms	646 ms
20	60 ms	180 ms	180 ms	420 ms
30	40 ms	120 ms	120 ms	280 ms

The International Morse code table

Every letter, figure and sign in section 1.1 of ITU-R M.1677-1. It has no upper and lower case, so decoded text comes back in capitals.

Sign	Code	Sign	Code	Sign	Code
0	-----	1	.----	2	..---
3	...--	4	....-	5	.....
6	-....	7	--...	8	---..
9	----.	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	--..
É	..-..	.	.-.-.-	,	--..--
:	---...	?	..--..	'	.----.
-	-....-	/	-..-.	(	-.--.
)	-.--.-	"	.-..-.	=	-...-
+	.-.-.	@	.--.-.

The Recommendation also gives five operating signs with no written character; they show here as <SN> understood, <HH> error, <AS> wait, <SK> end of work and <KA> starting signal, and you can type them. Not in the ITU table, but read and written here because German and Spanish text needs them: Ä .-.-, Ö ---., Ü ..--, ß ...--.., Ñ --.--. Anything else, such as ! or %, is left out and the page tells you.

For a better read

Use the original file
Each generation of re-recording adds noise. A file beats a recording of a speaker.
Cut it down to the Morse
Speech or music in the same file can take over as the loudest tone. Use the audio trimmer first if it does.
Check the tone
If the tone shown is not the one you hear, type the right one. That also lets you pick one of two signals at different pitches.
Watch the timing score
Good means the lengths match Morse timing. It does not prove every letter, so proofread anything that matters.

Morse is a code. Your meetings are not

This page reads one tone. For recorded speech, the ParrotNotes app records and transcribes a conversation and summarizes it for you.

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