Morse Code Converter: How It Works
Morse code encodes letters as sequences of short and long signals. It was the first practical digital communication system, it remains in active use for aviation navigation and amateur radio, and it is still one of the few codes a human can send and receive with no equipment at all.
The alphabet
| A ·− | B −··· | C −·−· | D −·· | E · | F ··−· |
| G −−· | H ···· | I ·· | J ·−−− | K −·− | L ·−·· |
| M −− | N −· | O −−− | P ·−−· | Q −−·− | R ·−· |
| S ··· | T − | U ··− | V ···− | W ·−− | X −··− |
| Y −·−− | Z −−·· | 1 ·−−−− | 2 ··−−− | 3 ···−− | 4 ····− |
| 5 ····· | 6 −···· | 7 −−··· | 8 −−−·· | 9 −−−−· | 0 −−−−− |
The lengths are not arbitrary. Samuel Morse and Alfred Vail counted the type in a printer's case to find which letters English uses most, then gave the commonest the shortest codes. E is a single dot, T a single dash, while rare letters like Q and Y take four elements each. It is a hand-built frequency encoding, arrived at roughly a century before information theory formalised the idea.
Timing is the code
Everything is measured in units, where one unit is the length of a dot.
| Element | Duration |
|---|---|
| Dot (dit) | 1 unit |
| Dash (dah) | 3 units |
| Gap between elements in a letter | 1 unit |
| Gap between letters | 3 units |
| Gap between words | 7 units |
The gaps carry as much information as the signals. Without correct spacing, ···−−−··· could be SOS, or IJS, or several other readings. This is why operators learn rhythm rather than symbols — experienced receivers hear whole words as patterns, not as sequences of dots to be decoded.
SOS and prosigns
SOS is ···−−−··· sent as one continuous nine-element sequence with no letter gaps — technically a prosign rather than three letters. It was chosen in 1906 purely because it is unmistakable and easy to send under stress; 'Save Our Souls' is a later invention.
Other common prosigns: ·−·−· (AR) ends a message, −·− (K) invites a reply, and ········ (eight dots) signals an error and a restart.
Still in use
- Aviation and marine navigation beacons transmit their identifier in Morse continuously, so a pilot can confirm which beacon they are receiving.
- Amateur radio — CW remains popular because a Morse signal punches through noise and interference at power levels where voice is unintelligible.
- Assistive communication — Morse can be produced by any single reliable movement, including a blink or a puff, which makes it valuable for people with severe motor impairment.
- Emergency signalling with light, sound, or a torch.
Learning it
Learn by sound, never by memorising a table of dots and dashes visually — people who learn visually plateau at around five words per minute because they translate in their head. The Koch method teaches two characters at full target speed and adds one at a time, which builds recognition rather than translation. Twenty words per minute is a realistic goal for a committed learner.