Morse code translator

How do you write, play and hear Morse code?

Turn text into Morse code and back, play it as sound or light, decode it from the microphone or camera, or key it by hand.

Message

Mode

Text

Morse code

... --- ...

1.6 s at 20 WPM

Display

Speed, tone and timing

Character speed

WPM

Tone pitch

Volume

Dot 60 ms, dash 180 ms, gap between letters 180 ms, between words 420 ms.

S O S

Letters, figures and punctuation. Write prosigns like <SK>.

Sound starts only when you press Play. Start at a low device volume.

Ä, Å, Ö, Ü and Ñ use common signals outside the ITU standard; dotted underlines mark them.

How to use

Choose Send to turn text into Morse code, Receive to turn Morse code into text, or Key to key Morse code by hand.
Send: type your text and press Play; the dot or dash being sent lights up. Choose Sound or Light: a small signal lamp, a large light at learning speed, the phone's flashlight, or a full-screen flash after a warning. Pick a speed, or open Speed, tone and timing for Farnsworth spacing, pitch and volume.
Save the sound as a WAV file or the code as a text file with the buttons under the code.
Receive: type dots and dashes, press Listen to decode tones from the microphone, choose a sound or text file, or start the camera and aim its square at a flashing light.
Key: hold the key or Space for a dash and tap it for a dot. The letters and your speed appear as you key. Full screen shows the text and the tape large in every mode.

Dot duration at common character speeds

Character speed (WPM)	Dot (ms)
5	240
10	120
15	80
20	60
25	48
30	40

Character speed sets the dot length; Farnsworth spacing lengthens the gaps.

How it works

Morse code writes each letter as short and long signals: dots and dashes. The International Morse code is defined by ITU-R Recommendation M.1677-1. Its timing has one unit: a dot lasts one unit, a dash three, the gap inside a letter one, between letters three and between words seven.

Speed is counted in words per minute (WPM) with the standard word PARIS, which is exactly 50 units long including its word gap. So one unit lasts 1.2 / WPM seconds: at 20 WPM a dot is 60 ms and a dash 180 ms. Farnsworth timing, as standardized by the ARRL, sends letters at the character speed c but stretches the gaps so the whole message runs at the slower speed s: a word gains ta = (60c − 37.2s) / (sc) seconds, shared 3 : 7 between letter and word gaps.

Receiving works on this device. For sound, the tool measures the strength of the tone in short slices (the Goertzel method); for light, the brightness of the camera's target square in each frame. Either way it decides when the signal is on, tells dots from dashes by their lengths, which also give the speed, and reads the gaps as letters and words; your own keying is read the same way. A camera sees about 30 frames a second and a dot needs about three of them, so light is reliable up to about 0.4 × frame rate WPM: 12 WPM at 30 frames a second.

Flashing light can trigger seizures. The accessibility rule WCAG 2.3.1 allows more than three flashes a second only over a small area, so the signal lamp stays under that area and the large light keeps to 5.5 WPM. The full-screen flash breaks the rule and asks first, every time. Ä, Å, Ö, Ü and Ñ are not part of the ITU code; the tool uses their common signals and marks them.

Frequently asked questions

What does WPM mean in Morse code?

Words per minute, counted with the 50-unit word PARIS. At 20 WPM, PARIS fits 20 times in a minute, so one unit is 60 / (50 × 20) = 0.06 seconds.

Why is PARIS the standard word?

Its dots, dashes and gaps add up to exactly 50 units, close to an average English word. Using one agreed word makes speeds comparable; the ARRL timing standard uses it.

What is Farnsworth timing?

Letters are sent fast enough that you learn their sound as a whole, with extra space between letters and words to give you time. ARRL practice below 18 WPM sends the letters at 18 WPM.

Which speeds are standard?

There is no single legal speed set. The quick picks are the speeds of the ARRL W1AW code practice (5, 7.5, 10, 13, 15, 20, 25, 30 and 35 WPM) and its bulletins (18 WPM).

Why is the light small?

Flashing faster than three times a second can trigger seizures. WCAG 2.3.1 allows it only over a quarter of a 10° field of view, 341 × 256 pixels on a 1024 × 768 screen (about 21,800 square pixels). The lamp is 128 pixels square, well under that, so it may flash at any speed. A larger light keeps to 5.5 WPM.

Is the microphone sound or the camera image recorded or sent anywhere?

No. Sound and image are analysed on your device while listening or the camera is on, and are not recorded, stored or uploaded. Stop, or leave the page, and the device is released.

Why does decoding make mistakes?

It needs a steady tone with clear gaps. Turn up the volume, lower the sensitivity in a noisy room, or set a fixed pitch. The first letters can change once the speed is known.

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