Letters in Morse Code

All 26 letters, grouped by how many elements they take rather than alphabetically — because the short ones are the common ones, and that is the order they become useful in.

Why the lengths are what they are

The story, which is well attested, is that Alfred Vail went to a printer and counted the type in the compositor's case to learn which letters English used most, and gave the shortest codes to those. E and T, the two commonest, got one element each. The rarer the letter, the longer the code, down to the four-element J, Q, Y and Z. It is the reason Morse is faster to send than a fixed-length code, and the reason the alphabet looks irregular: it is optimised for English text, not for tidiness.

That optimisation is language-specific. English is full of E and T; Czech and Portuguese are not to the same degree, so the code is slightly less efficient for them. The alphabet is international anyway, because the whole value of a standard is that two stations agree, and a code tuned per language would not be a standard.

Mirror pairs

Some letters are another letter backwards. A is di-dah and N is dah-dit; same two elements, opposite order. There are 6 such pairs, and they account for a large share of copying errors, because on paper they are the same marks rearranged and only by ear are they obviously different sounds.

• A .- and N -.
• B -... and V ...-
• D -.. and U ..-
• F ..-. and L .-..
• G --. and W .--
• Q --.- and Y -.--

Drill a mirror pair together, never one at a time. A drilled alone feels solid and then fails the moment it appears next to an N in real text, because what you learned was the letter and what you needed was the distinction.

Symmetric letters

The opposite case: letters that read the same backwards, so there is no mirror to confuse them with. E, H, I, K, M, O, P, R, S, T, X. They are disproportionately easy to hold onto under noise, and they make good anchors early on: a symmetric letter heard badly is still the same letter.

The two counting runs

E ., I .., S ..., H .... are the same sound repeated, distinguished only by how many times. So are T -, M --, O ---. These two runs are the whole reason the counting habit is a trap: they can be counted at five words a minute and cannot at fifteen, and a learner who relied on counting discovers it exactly there. Farnsworth spacing in the translator below exists to stop the habit forming: the letters stay fast, so a run is a shape, and only the gaps stretch.

Hear them

Frequently asked

Which letter is shortest?

E, a single dot, and T, a single dash. Samuel Morse’s collaborator Alfred Vail is said to have counted the type in a printer’s case to find out which letters English uses most, and assigned the shortest codes to those. It is why the alphabet is faster to send than a fixed-length code would be.

What order should I learn them in?

Not A to Z. The Koch method starts with two letters at full speed and adds a third only once you can copy the first two reliably, usually beginning with K and M, which sound nothing alike. Learning by length, as the table below is arranged, is the next best thing.

Should I count the dots?

No, and this is the single most common mistake. Counting works up to about 8 words per minute and then becomes impossible. Each letter has to become one rhythm you recognise whole; Farnsworth spacing in the translator exists for that: the letters stay fast while the gaps between them stretch.