Morse code represents letters, digits, and some punctuation as combinations of short and long signals — "dots" and "dashes." It's easy to forget that the code most people picture was built for one specific alphabet, and that "international Morse" is actually a revision of an earlier, incompatible American original.
American Morse vs. International Morse: two different codes
The code Samuel Morse and Alfred Vail devised in the 1830s-40s — now called "American Morse" — used timing that included dashes of different lengths and internal spaces within some letters, quirks that made it hard to transmit reliably over international cable lines. European telegraph operators revised it into what's now called International Morse (or Continental Morse) in the 1850s, simplifying the timing rules; that revision is the one standardized today and the one this tool implements. American Morse survived in US railroad telegraphy long after the international version became the global standard.
The encoding principle
The most common letters in English are encoded with the shortest sequences — "E" is a single dot, "T" is a single dash. Rarer letters get longer combinations. This approach — short codes for common symbols — makes transmission faster on average, and the same principle later became the basis for data compression algorithms like Huffman coding.
Where it's still used today
- Amateur radio — radio operators still use CW, a telegraphy mode based on Morse code, prized for working with very weak signals.
- Distress signals — the best-known example is SOS (three dots, three dashes, three dots), transmitted as one continuous signal with no letter gaps.
- Educational and recreational apps, puzzles.
Practical use
A Morse code converter is handy for quickly turning text into signals for learning or a puzzle, or the other way around — decoding a received sequence of dots and dashes back into text.
Transmission speed: WPM and Farnsworth timing
Morse speed is measured in words per minute (WPM), using the reference word "PARIS" to standardize the duration of a dot. Training often uses the Farnsworth method: the signals themselves are sent at full speed (to build ear-recognition of how they "sound"), while the pauses between letters and words are artificially lengthened — this makes recognition by ear easier without conditioning learners to a slow rhythm for individual signals.