How to Write a Sentence in Morse Code
To write a sentence in Morse code, convert each letter to its code, put a single space between letters, and put a slash (/) between words. “Hi you” becomes .... .. / -.-- --- ..-. When the sentence is sent as sound or light, the spaces become silences: one unit between the signals inside a letter, three units between letters, and seven units between words. A dot lasts one unit and a dash lasts three.
You can skip the manual work with the translator, which writes sentences in exactly this format. This page explains the rules, so you can write Morse by hand, read it back, and spot errors.
The 1-3-7 spacing rule
Every part of Morse timing is a multiple of one unit:
| Part | Length |
|---|---|
| Dot | 1 unit |
| Dash | 3 units |
| Gap between dots and dashes in one letter | 1 unit |
| Gap between letters | 3 units |
| Gap between words | 7 units |
How long a unit lasts depends on speed. Speed is measured in words per minute (WPM), using the word PARIS as the standard word. PARIS plus the gap after it is exactly 50 units, so at 20 WPM one unit is 60 milliseconds.
Take the two words IT IS, written .. - / .. .... IT takes 9 units, the word gap adds 7, and IS takes 11, for 27 units in all. At 20 WPM that’s about 1.6 seconds.
The gaps matter. A listener can only tell where a letter ends because the silence after it is longer than the silences inside it. A word break works the same way, with a still longer silence.
How to write word gaps in text
On paper or a screen you can’t show silence, so written Morse uses symbols and spaces instead:
- Letters get one space between them.
... . .is S, E, E. - Words get a slash between them, usually with a space on each side. This is the most common style, and it’s what the translator on this site produces.
- Some people use a vertical bar (|) instead of the slash. The translator reads it as a word break too.
- Others leave three or more spaces between words instead of a slash. The translator accepts this as well, but it’s fragile. Many apps and web pages shrink a run of spaces down to one, and your word breaks disappear.
The slash is the safest choice whenever you copy, paste, or text Morse.
One catch: the slash is also a real Morse character, -..-.. A slash sitting alone between spaces means “new word.” If you need to send an actual slash, as in a fraction or a radio callsign, send its code.
Punctuation in a Morse sentence
Punctuation marks have their own codes. Here are the three you’ll need most:
| Mark | Code |
|---|---|
| Period | .-.-.- |
| Comma | --..-- |
| Question mark | ..--.. |
A punctuation mark belongs to the word before it. It goes after the last letter with a normal letter gap, not a word gap. The full list, including the apostrophe, quote marks, and the signs operators use to start and end messages, is on the Morse code punctuation page.
You don’t have to include punctuation. Short messages often leave it out, and a sentence like ... . . / -.-- --- ..- / .- - / ---.. still reads fine without the period. Add punctuation when it changes the meaning, as a question mark does.
Worked example: “See you at 8.”
Here is the sentence built one word at a time:
| Word | Morse |
|---|---|
| SEE | ... . . |
| YOU | -.-- --- ..- |
| AT | .- - |
| 8. | ---.. .-.-.- |
Join the words with slashes and you get the full sentence:
... . . / -.-- --- ..- / .- - / ---.. .-.-.-
That’s 10 characters, counting the 8 and the period, across 4 words. Note how the period follows the 8 with a single space, the same as any other letter gap. Sent at 20 WPM, the sentence takes 117 units, or about 7 seconds.
Check your own sentences the same way. Write them out, paste them into the decoder, and confirm you get the original text back. If one letter comes out wrong, compare it against the Morse code alphabet. Numbers have their own five-signal codes, listed in the Morse code numbers chart.
Texting in Morse code
Texting someone in Morse uses the same written format: spaces between letters, slashes between words. Use a plain period for dots and a plain hyphen for dashes. Every keyboard has them, and every decoder reads them. The translator on this site also accepts middle dots, bullets, minus signs, en dashes, and underscores, in case someone sends you Morse typed with those.
If you want to type in Morse rather than send Morse as text, Gboard, Google’s keyboard app, has a Morse code input layout. You tap dots and dashes and it types the letters.
For ready-made messages, the phrases hub has common words and phrases already written out.
Common mistakes
Leaving out the letter spaces. Without spaces, a string of dots and dashes can split into letters in more than one way. HI is six dots. Written without its gap, it could just as well be SS (... ...) or several other pairs. Keep a space after every letter.
Using the same gap for letters and words. If word gaps are single spaces, the whole sentence reads as one long word. “Hi you” turns into HIYOU.
Ending with a plain period. In written Morse, a “.” is a dot, and a lone dot is the letter E. Write .... .. / -.-- --- ..- and finish it with a full stop out of habit, and the translator decodes it as HI YOUE. Use the period’s own code, .-.-.-, or leave it off.
Letting auto-correct change your dashes. Some apps and word processors turn two hyphens into one long dash. The translator here doesn’t read a long dash as Morse, and neither do many other decoders. Turn off auto-correct, or decode the message yourself before you send it.
Stretching letter gaps in audio. If the gaps between letters drift close to seven units, a listener hears new words. Keep letter gaps at three units and word gaps at seven.
FAQ
How do you write a sentence in Morse code?
Convert each letter to its Morse code, put one space between letters, and put a slash (/) between words. For example, “hi you” is .... .. / -.-- --- ..-. Punctuation marks have their own codes and attach to the end of the word before them.
How do you show a space between words in Morse code?
In writing, use a slash with a space on each side. Some people use a vertical bar or three or more spaces instead. In sound or light, a word space is a silence of seven units, compared with three units between letters.
How long is the pause between words in Morse code?
Seven units, where one unit is the length of a dot. The pause between letters is three units, and the pause between dots and dashes inside a letter is one unit. At 20 words per minute, one unit is 60 milliseconds, so a word gap is 420 milliseconds.
How do you write a period or question mark in Morse code?
A period is .-.-.- and a question mark is ..--... Write the mark straight after the last letter of the word with a normal letter space, not a word gap. Don’t end a Morse sentence with a plain “.” character. A decoder reads it as a dot, which is the letter E.
Can you text in Morse code?
Yes. Type periods for dots and hyphens for dashes, a space between letters, and a slash between words. The person receiving it can decode it by hand or paste it into a decoder. Gboard on phones also has a Morse code keyboard layout that turns tapped dots and dashes into letters.