Decoding guide
How to Read Morse Code
Reading Morse code means turning a string of dots and dashes, or a rhythm of beeps, back into letters. This guide covers reading by sight, reading by ear, the Morse code tree, and worked examples you can decode step by step.
What you need to know before you start
Morse code is built from two signals and three kinds of silence. A dot (·) is one unit long. A dash (–) is three units long. Inside a letter, symbols are separated by one unit of silence. Letters are separated by three units, and words by seven. That is the whole grammar. Every method of reading Morse, by sight or by ear, comes down to one job: find the gaps, because the gaps tell you where letters and words begin and end.
Written Morse makes this easy. A space separates letters and a slash (or three spaces) separates words:
·–· · ·– –·· / –– · → READ ME
How to read Morse code by sight
If you are looking at dots and dashes on paper, a screen or a bracelet, follow these four steps:
- Find the word gaps first. Look for slashes, wide spaces or line breaks. Mark them. Now you are decoding one word at a time.
- Split each word into letters at the single spaces. Each group between spaces is exactly one character.
- Count the symbols in the group. One symbol means E or T. Two symbols means I, A, N or M. Three means S, U, R, W, D, K, G or O. Four means one of the remaining 12 letters. Five symbols is always a digit.
- Look up the pattern in the chart, or walk the tree below: start at the top and take the dot branch or the dash branch for each symbol.
With practice you stop counting and simply recognize .- as A the way you recognize a word. Until then, the counting trick narrows every letter to a handful of candidates.
Letters grouped by length
| Symbols | Letters |
|---|---|
| 2 | A .- I .. M -- N -. |
| 4 | B -... C -.-. F ..-. H .... J .--- L .-.. P .--. Q --.- V ...- X -..- Y -.-- Z --.. |
| 3 | D -.. G --. K -.- O --- R .-. S ... U ..- W .-- |
| 1 | E . T - |
How to read Morse code by ear
Listening is the real skill, and it is different from reading on paper: you cannot pause, and you cannot count fast enough. Operators learn each character as a rhythm. They do not hear "dot dash"; they hear di-dah and know it is A. The convention for saying Morse out loud is dit for a dot, dah for a dash, and di for a dot that is not the last symbol. B is dah-di-di-dit; C is dah-di-dah-dit.
Three habits make listening easier:
- Write the letter the moment you recognize it, then forget it. Holding letters in your head while listening for the next one is how you lose the whole word.
- Leave a blank for anything you miss. Most words are obvious from context once you have most of the letters.
- Learn the sound of silence. The three-unit letter gap and the seven-unit word gap have their own feel. If you hear a pause and are unsure whether it was a letter or a word gap, it was almost certainly a letter gap; word gaps are long enough to be obvious.
If you want to train this properly, the learning guide explains the Koch method, and the practice quiz plays random characters for you to identify.
Dichotomic table
The Morse code tree
Start at the top. For each symbol you hear or see, go left for a dot and right for a dash. Wherever you stop is your letter. Tap any node to hear it.
The tree is also called the dichotomic table, and it is the fastest way to decode by sight when you do not yet know the alphabet. Each level down adds one symbol. Notice the symmetry: everything under E starts with a dot, everything under T starts with a dash. The same tree is sometimes called the Morse code binary tree, because every node has exactly two branches.
Worked examples: decoding step by step
Example 1: a single word
.... . .-.. .--.
- No slash, so it is one word. Four groups, so four letters.
- .... four dots. Tree: dot → E, dot → I, dot → S, dot → H.
- . one dot. E.
- .-.. dot → E, dash → A, dot → R, dot → L.
- .--. dot → E, dash → A, dash → W, dot → P.
Result: HELP.
Example 2: two words
--. --- --- -.. / .--- --- -...
- One slash, so two words: --. --- --- -.. and .--- --- -....
- First word: --. dash → T, dash → M, dot → G. --- three dashes → O. Again O. -.. dash → T, dot → N, dot → D. GOOD.
- Second word: .--- dot, then three dashes → J. --- → O. -... dash, three dots → B. JOB.
Result: GOOD JOB.
Example 3: by ear
Press play and try to write the letters as they arrive. There are three short words. Check your answer with the decoder afterwards.
The pattern everyone should recognize: ··· ––– ···
SOS is sent as one continuous pattern, ...---..., with no letter gaps, which is why it is often written with an overbar. Three short, three long, three short. By ear it sounds like di-di-dit dah-dah-dah di-di-dit. By light it is three quick flashes, three long, three quick. By tapping it is three quick taps, three slow (or hard) ones, three quick. If you learn nothing else, learn this. Read more on the SOS in Morse code page.
Reading Morse code from light or taps
The rules are identical; only the signal changes. With a flashlight, a short flash is a dot and a flash roughly three times as long is a dash. Light Morse is sent slowly, usually 5 to 8 words per minute, because the eye is slower than the ear. With taps or knocks, the sender cannot make a long sound, so dashes are usually signaled by a longer press, a harder knock or a double tap; agree on the convention first. Our light and blinking guide and tapping guide cover both in detail, with simulators.
Next step
Practice reading Morse code
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FAQ
Frequently asked questions
How do you read Morse code?
Split the message at the word gaps (slashes or long pauses), then at the letter gaps (single spaces or short pauses). Each group of dots and dashes between gaps is one character. Look it up in the chart, walk the Morse code tree one symbol at a time, or, once trained, recognize the rhythm directly.
What is the Morse code tree?
A diagram (also called the dichotomic table) in which every branch to the left adds a dot and every branch to the right adds a dash. Starting from the root, E is one dot and T is one dash; below E come I and A, below T come N and M, and so on. You decode a letter by following its symbols down the tree.
How do I understand Morse code by ear?
Learn each character as a rhythm rather than counting dots and dashes. Practice with characters sent at 15–20 WPM with long gaps between them (Farnsworth timing), write each letter immediately, and leave blanks for anything you miss. Daily ten-minute sessions get most people reading the whole alphabet in a few weeks.
How do I decode Morse code quickly without learning it?
Paste the dots and dashes into our Morse code decoder. It accepts dots, periods, hyphens, en dashes and typographic bullets, treats a slash or three spaces as a word gap, and shows the text instantly.
How many dots and dashes is each letter?
Between one and four. E and T have one symbol; I, A, N and M have two; S, U, R, W, D, K, G and O have three; the other twelve letters have four. All digits have exactly five symbols, and most punctuation marks have six.
Why is there no gap inside SOS?
SOS is defined as a single prosign, a nine-symbol pattern sent without letter spacing, so it is unmistakable even on a weak or noisy signal. Written with an overbar, it is technically not the three letters S, O and S but one distress symbol.
Try decoding a message yourself
Paste any dots and dashes into the decoder and compare with what you read.