How Morse Code Works: Dots, Dashes, Spacing and Timing

Morse code represents each letter, digit and punctuation mark as a short sequence of two signals: a short "dot" (dit) and a long "dash" (dah). What makes it readable is timing: a dash lasts three times as long as a dot, letters are separated by a gap of three dot-lengths, and words by seven. In written form, those gaps become a space between letters and a slash between words.

Here's how the system fits together, and how to read and write it as text.

Why are some letters shorter than others?

Morse code was designed for speed. The most common letters in English got the shortest codes, so operators could send messages faster:

Letter	Code	Length
E	.	1 symbol
T	-	1 symbol
A	.-	2 symbols
S	...	3 symbols
Q	--.-	4 symbols
0	-----	5 symbols

E and T, the two most frequent letters, are a single signal each. Rare letters like Q, Y and Z get four. Digits are all five symbols long and follow a neat pattern: 1 is .----, 2 is ..---, and so on up to 5 (.....), after which dashes take over again.

The 1-3-7 timing rule

Everything in Morse is measured in "units", where one unit is the length of a dot:

• Dot: 1 unit
• Dash: 3 units
• Gap between the dots and dashes inside one letter: 1 unit
• Gap between letters: 3 units
• Gap between words: 7 units

These ratios are set out in the international standard for Morse (ITU-R M.1677). Get the spacing wrong and the message becomes ambiguous: .. - with a letter gap is "IT", but run together as ..- it's "U".

A worked timing example

How long does "SOS" take to send at 20 words per minute?

1. S = ... → 3 dots + 2 inner gaps = 5 units.
2. O = --- → 3 dashes (9 units) + 2 inner gaps = 11 units.
3. S again = 5 units.
4. Two letter gaps between them = 2 × 3 = 6 units.

Total: 5 + 11 + 5 + 6 = 27 units. Operators use the formula unit length in milliseconds = 1200 ÷ words per minute, so at 20 WPM one unit is 60 ms, and "SOS" takes 27 × 60 = 1.62 seconds.

In real distress calls, SOS is actually sent as one continuous sequence, ...---..., without letter gaps. It was chosen because the pattern is unmistakable, not because the letters stand for anything.

How Morse is written as text

On paper and on screen, the timing becomes punctuation. The Morse Code Converter uses the most common convention:

• Dots and dashes: . and -
• Between letters: one space
• Between words: / (a slash)

So "Hello World" becomes:

.... . .-.. .-.. --- / .-- --- .-. .-.. -..

When decoding, the tool is flexible about what you paste. It accepts • and · for dots and −, –, — or _ for dashes, and it treats a slash, a vertical bar (|) or three or more spaces as a word break. That helps when you copy Morse from a puzzle, a book or a website that uses typographic symbols.

What can and can't be translated

Supported: the letters A–Z, digits 0–9 and common punctuation: . , ? ' ! / ( ) & : ; = + - _ " $ @.

Not supported: accented letters (é, ñ, ü) and other symbols. These are dropped silently rather than causing an error. For example, "café" encodes as -.-. .- ..-., which decodes as "CAF". If your message contains accents, replace them with plain letters first.

Morse also has no lowercase. Decoded text always comes out in capitals.

How to translate Morse code

1. Type text or paste Morse into Text or Morse code, or click Load sample (it loads "SOS Hello World").
2. Leave Direction on Detect automatically: input made only of dots, dashes, spaces and slashes is decoded; anything else is encoded. Pick Text → Morse or Morse → Text to force it.
3. Read the translation in Result. It updates as you type.
4. Click Copy or Download.

Translation runs in your browser, so your messages aren't sent anywhere.

FAQ

Why did my decoded message come out with letters missing?

A sequence that doesn't match any character, often from a typo like .-.-.-. or a missing space between letters, is skipped. Check the spacing first: two letters run together usually form a different letter or no letter at all.

Is American Morse the same as this?

No. The converter uses International Morse code, the version used in amateur radio and aviation today. The original American Morse used for 19th-century telegraphs had different codes for several letters and internal spaces within some characters.

How can I practice reading Morse?

Encode short words you know, cover the text, and try to decode them back. Start with E, T, A, N, I and M, the shortest codes, then add letters gradually.

Try encoding your name in the Morse Code Converter.