Morse Code

What is Morse code?

Morse code is a communication system that encodes text characters as sequences of dots (short signals) and dashes (long signals). Developed by Samuel Morse and Alfred Vail in the 1830s for use with the telegraph, it was the primary method of long-distance communication before the telephone. Each letter, number, and some punctuation marks have a unique pattern.

This tool converts text to Morse code and Morse code to text. It displays the dot-dash patterns and can play audio representations. Morse code is still used today by amateur radio operators (hams), in aviation and maritime emergencies, and as an accessibility tool for people with limited mobility who can communicate using simple binary inputs.

How to use this tool

Type text to see it converted to Morse code (dots and dashes) instantly. Paste Morse code using dots (.) and dashes (-) with spaces between letters and slashes between words to decode it back to text. The tool supports letters A-Z, numbers 0-9, and common punctuation.

The Morse code alphabet

• A: .- | B: -... | C: -.-. | D: -.. | E: . (the shortest code, for the most common English letter).
• S: ... | O: --- | Together they form SOS (...---...), the universal distress signal.
• Numbers use five symbols each: 1 is .---- and 0 is -----.
• A dash is three times the length of a dot. Spacing between letters is three dot-lengths. Spacing between words is seven dot-lengths.

Timing rules: how Morse code is measured

International Morse Code uses a unit-based timing system. A dot (dit) lasts exactly 1 unit. A dash (dah) lasts 3 units. The gap between symbols within the same letter is 1 unit. The gap between letters is 3 units. The gap between words is 7 units, represented in this tool as a forward slash (/).

These ratios are what make Morse code readable at any speed. Operators can slow down or speed up while keeping the relative durations the same. At a common training speed of 13 words per minute, one unit is approximately 92 milliseconds.

Worked example: spelling “SOS”

The distress signal SOS is encoded as three letters: S, O, S. S is “...” (three dots), O is “---” (three dashes), and S again is “...”. Written continuously with standard spacing: “... --- ...”. Note that within each letter the symbols are separated by 1-unit gaps, and the letters themselves are separated by 3-unit gaps. The full sequence sounds like: dit-dit-dit [pause] dah-dah-dah [pause] dit-dit-dit.

Another example: the word MORSE. M is “--”, O is “---”, R is “.-.”, S is “...”, E is “.”. In Morse notation: “-- --- .-. ... .”. Use the tool above to encode any word and press Play Audio to hear the correct timing.

Prosigns and common operating signals

Prosigns are procedural signals made of two letters sent without an inter-letter gap, creating a unique combined code. Common prosigns in amateur radio and maritime use include: AR (“.-.-.”, end of message), SK (“...-.-”, end of contact), BT (“-...-”, paragraph break or separator), and KN (“-.--.”, invitation to a specific station to reply). These are distinct from normal two-letter combinations because the gap is omitted.

The SOS distress signal (“...---...”) is itself sent as one continuous sequence without letter gaps, making it instantly recognisable and impossible to confuse with regular text.

History and legacy

The first telegraph message ('What hath God wrought') was sent by Samuel Morse in 1844 between Washington, D.C. and Baltimore. Morse code transformed global communication, enabling instant long-distance messaging for the first time. It played crucial roles in both World Wars, maritime safety (the Titanic's distress calls were in Morse code), and aviation. While largely replaced by digital communication, Morse code remains part of amateur radio licensing requirements worldwide.

How to learn Morse code

The most effective method for learning Morse code is the Koch method, developed by Ludwig Koch in the 1930s. Rather than starting with slow, drawn-out sounds, the Koch method teaches characters at full operating speed (typically 15–20 WPM) from the very first lesson, with only two characters at a time. Once you can copy those two characters at 90% accuracy, a third character is added. This approach trains the brain to recognise the rhythmic sound pattern of each character rather than consciously counting dots and dashes.

Farnsworth timing is a complementary technique where characters are sent at a higher speed (e.g. 18 WPM character speed) but extra spacing is inserted between letters and words so the overall throughput feels slower. This gives a beginner time to process each character while still hearing it at the speed it will sound like in real operation. Many modern training apps, including the free LCWO (Learn CW Online) website, combine both techniques.

Beginners should practise at least 15 minutes per day. Most people can copy simple text at 5 WPM after four to six weeks of consistent practice. Copying by ear is far more important than sending; once your ear is trained, the hand follows naturally.

Modern uses of Morse code

Amateur (ham) radio operators worldwide still use Morse code, known in the hobby as CW (continuous wave). Although most countries eliminated the Morse proficiency requirement for amateur licensing in 2003 following an ITU decision, many operators choose to learn it. CW transmission is highly efficient — it requires minimal bandwidth and can be decoded by the human ear even through heavy static and interference that would render voice communications unintelligible.

Aviation still uses Morse identifiers. Non-directional beacons (NDBs) and VOR navigation aids broadcast their two- or three-letter identifier in Morse code continuously so pilots can verify the correct station. Pilots are trained to recognise these audio idents during navigation.

Morse code has significant value as an accessibility and augmentative communication tool. People with severe motor disabilities who cannot speak or use a keyboard can operate switches, eye blinks, or single-muscle inputs to enter Morse code, which software then converts to text or speech. Both iOS and Android include built-in Morse code input keyboards for this purpose.

Common mistakes when reading and sending Morse code

• Incorrect spacing: the most frequent error is inconsistent gaps between letters and words. A 3-unit gap that accidentally becomes 7 units makes the decoder insert an unwanted word break.
• Counting instead of listening: beginners who mentally count “dot dot dash” instead of learning the sound pattern of each character (U sounds like “dit-dit-dah”) hit a ceiling around 10 WPM and cannot improve further.
• Confusing similar codes: N (“-.”) and D (“-..”), or K (“-.-”) and C (“-.-.”) are commonly mixed up. Focused practice on confusable pairs resolves this quickly.
• Sending too fast before the ear can keep up: confidence builds faster by sending slightly slower than your maximum comfortable receive speed, not faster.

Frequently asked questions

What does SOS stand for?

SOS does not actually stand for anything — it was chosen as the international distress signal in 1906 because its Morse code pattern (...---...) is easy to send, recognize, and distinguish from other signals. The popular interpretations 'Save Our Souls' and 'Save Our Ship' are backronyms invented after the signal was adopted.

How fast can Morse code be transmitted?

Skilled operators can send and receive 20-30 words per minute (WPM). The world record for Morse code reception is over 75 WPM. At standard 13 WPM, the word 'PARIS' takes exactly 1 minute to send (this is the calibration standard). Automated transmission can be much faster, but human reception becomes unreliable above 40 WPM for most operators.

Do I still need Morse code for an amateur radio licence?

In most countries, no. The ITU removed the international requirement for a Morse code proficiency test in 2003, and nearly all national regulators followed suit. The United States eliminated the requirement in 2007. However, some countries and advanced licence classes still test Morse code, and many operators learn it by choice for its technical advantages and the active CW (Morse) community on the ham bands.

Can Morse code be used without a radio?

Yes. Morse code can be transmitted by any medium that can convey two distinct states: light (signalling lamps, torches), sound (buzzers, whistles, ship horns), electrical pulses, physical taps, flag movements, or even blinks. This versatility is why it remains useful in emergencies and as an accessibility input method when other communication channels are unavailable.