Morse code, developed by Samuel Morse and Alfred Vail for the electric telegraph in the 1830s and 1840s, writes every letter as a short sequence of dots (short signals) and dashes (long signals). The international version standardised by the ITU is still used by radio amateurs, in aviation and maritime navigation beacons, and as an assistive input method; SOS (··· −−− ···) remains the best-known distress signal.
The code is designed for efficiency: the most frequent English letters get the shortest codes – E is a single dot, T a single dash – while rare letters like Q (−−·−) are longer. Timing is just as important as the symbols. A dash lasts three dots, the silence inside a letter one dot, between letters three dots and between words seven dots. Speed is measured in words per minute using the standard word PARIS, which is exactly 50 units long, so at 20 WPM a dot lasts 1.2 ÷ 20 = 0.06 s.
Type plain text to get Morse, or paste dots and dashes (·, −, _ and • are accepted too) to decode. Separate letters with one space and words with a slash or two spaces.
How to use the Morse Code Translator
- Direction
- Text or Morse code
- Symbols in the output
- Sending speed
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How it works
Text is upper-cased and each character is looked up in the ITU table; letters are joined with spaces and words with “ / ”. Morse input is split into words at slashes or double spaces and into letters at single spaces, and each code is looked up in reverse. The timing counts dot units according to the ITU spacing rules.
Worked example
“SOS help” encodes to … — … / …. . .-.. .–.. Counting units: S (···) = 5, O (−−−) = 11, S = 5, plus two 3-unit letter gaps = 27; the word gap adds 7; HELP = 7 + 1 + 9 + 11 + three letter gaps 9 = 37. Total 71 units. At 20 WPM one unit is 60 ms, so the message takes 71 × 0.06 = 4.26 s.
Morse alphabet
| A–I | J–R | S–Z | Digits |
|---|---|---|---|
| A ·− B −··· C −·−· | J ·−−− K −·− L ·−·· | S ··· T − U ··− | 1 ·−−−− 2 ··−−− |
| D −·· E · F ··−· | M −− N −· O −−− | V ···− W ·−− X −··− | 3 ···−− 4 ····− 5 ····· |
| G −−· H ···· I ·· | P ·−−· Q −−·− R ·−· | Y −·−− Z −−·· | 6 −···· … 0 −−−−− |
Tips
- Check datasheet values (tolerance, temperature) before building.
- Every field has its own unit menu.
- Leave a safety margin on current, power and voltage ratings.
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Common mistakes to avoid
- Mixing bits and bytes, or 1000- and 1024-based units.
- Ignoring tolerances of real components.
- Using a formula outside its valid range (e.g. thin traces, high frequency).
Formula
Dot = 1 unit · dash = 3 units · gap inside a letter = 1 · between letters = 3 · between words = 7Dot length (s) = 1.2 ÷ WPM (PARIS standard: one word = 50 units)Worked example
Inputs — Direction: Detect automatically; Text or Morse code: SOS help; Symbols in the output: Dots and hyphens . -; Sending speed: 20 WPM.
Results — Result = ... --- ... / .... . .-.. .--.; Direction used = Text → Morse code; Message length = 71 units; Transmission time = 4.26 s; Dot length = 60 ms; Dash length = 180 ms.
Key terms
- Dit and dah
- The spoken names for a dot and a dash.
- Unit
- The length of one dot; all Morse timing is a multiple of it.
- WPM
- Words per minute, based on the 50-unit word PARIS.
- Prosign
- A procedural signal such as SK (end of contact) sent as one character.
Frequently asked questions
What is SOS in Morse code?
··· −−− ··· (three dots, three dashes, three dots), sent as one continuous signal.
How do I separate letters and words?
One space between letters and a slash “/” or two spaces between words.
How long is a dot at 20 WPM?
1.2 ÷ 20 = 0.06 s, so a dash lasts 0.18 s and a word gap 0.42 s.
Which letter has the shortest code?
E, a single dot; T is a single dash. Both are the most frequent letters in English.
What does 143 mean?
It is pager slang for “I love you” (1, 4 and 3 letters), not Morse code; in Morse it would be ·−−−− ····− ···−−.
Is Morse code still used?
Yes – by amateur radio operators, in aviation navigation beacons (VOR, NDB identifiers) and as an accessibility input method.
Does Morse code have lowercase letters?
No. Morse has no case, so decoded text is in capitals.
What formula does the Morse Code Translator use?
Dot = 1 unit · dash = 3 units · gap inside a letter = 1 · between letters = 3 · between words = 7.