Morse code turns letters into two sounds: a short dot (·) and a long dash (—). It was built for the telegraph in the 1840s, and it still works today over anything that can be switched on and off — radio, a flashlight, even tapping on a wall.
The alphabet is built on frequency
Samuel Morse and Alfred Vail did something clever: they gave the most common letters the shortest codes. In English, E is the most frequent letter, so E is a single dot (·). T is a single dash (—). Rare letters like Q (--.-) and Y (-.--) get longer sequences. That’s why sending Morse is faster than a fixed-length code would be.
A quick reference: A–Z and 0–9
Here is the full International Morse alphabet. Read . as a dot and - as a dash:
| Letter | Code | Letter | Code | Letter | Code |
|---|---|---|---|---|---|
| A | .- | J | .--- | S | … |
| B | -… | K | -.- | T | - |
| C | -.-. | L | .-.. | U | ..- |
| D | -.. | M | — | V | …- |
| E | . | N | -. | W | .— |
| F | ..-. | O | --- | X | -..- |
| G | —. | P | .—. | Y | -.— |
| H | … | Q | —.- | Z | —.. |
| I | .. | R | .-. |
| Digit | Code | Digit | Code |
|---|---|---|---|
| 0 | ----- | 5 | … |
| 1 | .---- | 6 | -… |
| 2 | ..--- | 7 | —… |
| 3 | …— | 8 | ---.. |
| 4 | …- | 9 | ----. |
The digits are pleasingly regular: 1–5 add dashes from the left, 6–0 add dots, so every one is exactly five symbols long.
The three gaps that make or break a message
Most people learn the dots and dashes and forget the part that actually carries meaning: timing. If a dot is one unit long, then:
- A dash is three units.
- The gap inside a letter (between its own dots and dashes) is one unit.
- The gap between letters is three units.
- The gap between words is seven units.
Get the spacing wrong and ... --- ... (three letters: S, O, S) collapses into one long unreadable string. When you write Morse down, the convention is a space between letters and a / between words — which is exactly what the Morse code translator uses.
Why SOS is not “save our ship”
The famous distress signal ···———··· (SOS) was chosen because it’s simple and unmistakable to send and hear, not because it stands for anything. “Save our ship” and “save our souls” are backronyms invented later. As a continuous signal it’s just three short, three long, three short.
What Morse can’t do
Standard Morse covers A–Z, the digits 0–9 and a handful of punctuation marks. There’s no case (SOS and sos are identical), and no mapping for Chinese, emoji or accented letters — those simply have no code. Hear the rhythm by pressing play in the translator; the beeps build your ear faster than any chart.
A short history
Morse code grew out of the electric telegraph. Samuel Morse and Alfred Vail developed the code in the late 1830s and 1840s, building on Joseph Henry’s work with the electromagnet; matching the shortest codes to the most common letters is largely credited to Vail. The first public line opened in 1844, when Morse sent “What hath God wrought” from Washington to Baltimore.
The version almost everyone uses today is International Morse Code, refined from Morse’s original “American” code in the 1840s and standardized in 1865. At sea, Morse carried distress calls for most of the 20th century — SOS became the worldwide standard in 1906 — until the Global Maritime Distress and Safety System retired it in 1999. It lives on in amateur radio (where operators call it CW) and in the identifiers that aviation beacons still tap out.
How to learn it by ear
The mistake most beginners make is memorizing the chart by sight and counting dots. Fluent operators hear each letter as a rhythm, not a count. Two classic methods help:
- The Farnsworth method plays each character at full speed but stretches the gaps between them, so you learn the true shape of a letter while your brain still has time to react. You shrink the gaps as you improve.
- The Koch method starts with just two characters at full target speed and adds one more each time you hit about 90% accuracy.
Say the sounds out loud — “di-dah” for A, “dah-di-di-dit” for B — and press play in the Morse code translator to train your ear. If you enjoy compact ways of representing information, the guide to binary, hex and decimal shows how computers do the same job with numbers.
Related tools
- Want a different way to encode text? Try Base64 or the number base converter.