Morse Code Generator

Long read • ~6 minutes

A short history of Morse code

The story of how dots and dashes carried civilization’s most important messages for nearly two centuries — and why operators still send them today.

Quick answers

When was Morse code invented?
It was developed in the 1830s for the electric telegraph, and the first official message was sent on May 24, 1844, from Washington, D.C. to Baltimore.
Who invented it?
Samuel F. B. Morse built the telegraph and gave the code its name; his partner Alfred Vail is widely credited with much of the code itself. More in who invented Morse code.
Why was it invented?
A telegraph wire can only carry an electrical pulse switched on and off, so letters had to be turned into patterns of short and long pulses before a message could travel down the line.
Is it still used?
Yes — by amateur radio operators, by aviation beacons that identify themselves in Morse, and for emergency signalling. Ships stopped relying on it for distress calls in 1999. See why Morse code is still used today.

Origins (1830s–1844)

In the 1830s Samuel F. B. Morse, an American painter, began collaborating with the inventor Alfred Vail and the chemistry professor Leonard Gale on a practical electric telegraph. Morse first planned to send only numbers, looked up in a codebook; it was replaced by an alphabet code developed by Vail in 1840 — what would later be called American Morse. The official first message was sent on May 24, 1844, from the Supreme Court chamber in the U.S. Capitol to the B&O railroad's Mount Clare Station in Baltimore: “What hath God wrought.”

Morse was not the only dot-based code of its century. Louis Braille had published his six-dot reading system for blind readers in 1829, more than a decade before that first telegraph message — a code built for touch and the page rather than for distance and the wire. We compare the two in Morse code vs braille, and our sister site BrailleChart covers braille's own history.

From American Morse to International Morse (1848–1865)

American Morse used dashes of different lengths and spaces inside some letters. In 1848 Friedrich Clemens Gerke reworked it for the telegraph line between Hamburg and Cuxhaven in Germany, changing nearly half the alphabet and all the numerals and doing away with the different dash lengths and internal spaces. A version of Gerke's code was standardised by the International Telegraph Convention in Paris in 1865 and became International Morse Code; in the U.S., American Morse remained the standard for landline telegraph companies such as Western Union. Today the ITU maintains the international standard as ITU-R M.1677-1. More in International vs American Morse.

Wireless and the SOS distress signal (1903–1912)

Marconi’s wireless telegraphy turned Morse into a maritime backbone. At first there was no common distress call: Marconi operators used CQD from 1904, and the US Navy proposed the flag signal NC. Germany introduced SOS — three dots, three dashes, three dots — in its radio regulations of 1905, and the 1906 Berlin International Radiotelegraphic Conference adopted it for everyone. It became internationally effective on July 1, 1908, and in 1912 the operators of RMS Titanic sent both CQD and SOS.

The world wars and aviation (1914–1945)

Morse radiotelegraphy carried military traffic in both world wars, and code-breakers worked on it: early in the First World War, Germany briefly tried modified "dotty" and "dashy" Morse, which Allied intelligence broke quickly. Aviation adopted Morse for radio beacon identification, and VOR and NDB beacons still send their identifiers in Morse today; pilots check them by ear against the chart. See Morse code in aviation.

The end of maritime Morse (1999)

By February 1, 1999, ships had to carry the satellite-based Global Maritime Distress and Safety System (GMDSS), which replaced Morse for ocean distress after nearly a century. The Maritime Radio Historical Society dates the last commercial Morse transmission in the U.S. to July 12, 1999; it signed off with Morse's 1844 message, “What hath God wrought.”

Why Morse is still alive in amateur radio

In ham radio, Morse — known as CW (continuous wave) — survives because it gets through. A CW signal needs a bandwidth on the order of 100 Hz, against roughly 2.4–3 kHz for voice (SSB), so the receiver can filter out far more noise. That is why low-power (QRP) operators make long-distance contacts in CW that would be too weak to understand on voice. There’s also a tactile pleasure to it that keeps people coming back to the key.

Learn it the modern way

Sources / further reading: ITU-R M.1677-1 (2009); International Radiotelegraph Convention, Berlin (1906), Service Regulation XVI; Wikipedia, “Morse code”, “Samuel Morse” and “SOS” and the sources they cite; Maritime Radio Historical Society (radiomarine.org); IMO GMDSS timeline.