Morse Code Generator
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THE SPACE BETWEEN SIGNALS

Morse Code Timing

A message needs silence as much as sound. The short and long pauses tell your listener where a letter ends and a new word begins.

Five rules, one unit

International Morse timing
Part of the messageLengthAt 20 WPM
Dot1 unit60 ms
Dash3 units180 ms
Gap inside a letter1 unit60 ms
Gap between letters3 units180 ms
Gap between words7 units420 ms

Hear the difference

I · ..

Dot, short gap, dot.
60 + 60 + 60 = 180 ms.

EE · . .

Dot, letter gap, dot.
60 + 180 + 60 = 300 ms.

E T · . / -

Dot, word gap, dash.
60 + 420 + 180 = 660 ms.

Try these messages in the generator at 20 WPM. Turn the speed down if the pauses are difficult to hear.

Read Morse code with a flashlight

Light uses the same pattern as sound: the light is on for a mark and off for a pause. Keep the dot length steady so someone watching can tell the gaps apart.

  • Light on for 1 unit: a dot. Light on for 3 units: a dash.
  • Light off for 1 unit between marks in the same letter.
  • Light off for 3 units between letters, or 7 units between words. These are total gap lengths.

For A (.-), the light is on for one unit, off for one, then on for three. To send a second letter, leave it off for three units before that letter starts.

To preview the rhythm, enable the optional light signal in the generator. It starts only when you choose Play Morse, uses a small area, and is limited to 7 WPM. Set volume to 0% for a silent preview. Flashing light can affect sensitive users; avoid this mode if that applies to you. The preview is disabled when your device requests reduced motion. You can always read the dots and dashes or use sound instead.

Why WPM is measured with PARIS

The standard word PARIS, including the word gap after it, takes 50 units. At 20 words per minute, one full PARIS cycle takes 3 seconds, making one dot 3 ÷ 50 = 0.06 seconds. More generally, a dot lasts 1.2 ÷ WPM seconds.

Our downloads finish when the final mark finishes; they do not add a trailing word gap. PARIS therefore lasts 2.58 seconds at 20 WPM. Add its 0.42-second word gap and the standard cycle is exactly 3 seconds.

Keep the gaps from adding up

A letter gap is three units in total, rather than a one-unit symbol gap followed by three more units. A word gap is seven units in total. This matters when building an LED project; our Arduino sketch includes the complete gap lengths.

Reference: ITU-R M.1677-1.