At OnlineMorseCode, accuracy is our highest priority. Morse code is a precise communication system — a single wrong dot or dash changes the meaning of a character completely. This page explains the standards and sources we use to ensure all Morse code on this site is correct.
Our Primary Source: ITU-R M.1677-1
All Morse code on OnlineMorseCode follows ITU-R M.1677-1 — the International Telecommunication Union Recommendation for International Morse Code. This is the global official standard for Morse code, updated most recently in 2009, and used by:
- Amateur radio operators worldwide
- Maritime and aviation communicators
- Military and emergency services
- Accessibility technology developers
The ITU standard defines the exact dot-dash pattern for every character in the standard International Morse Code alphabet (A–Z, 0–9, and punctuation), as well as regional extensions for Arabic, Hebrew, Cyrillic, Spanish, French, and other languages.
Timing Standards
Correct Morse code is not just about the right dot-dash patterns — it also requires correct timing ratios. We implement the precise ITU timing specification:
Dot duration
1 unit — the base unit of all Morse timing. All other durations are measured relative to the dot.
Dash duration
3 units — exactly 3× the dot duration. A dash that is shorter or longer is incorrect Morse code.
Inter-element gap
1 unit — the pause between dots and dashes within a single character.
Inter-letter gap
3 units — the pause between separate characters.
Inter-word gap
7 units — the pause between separate words.
WPM measurement
Speed is measured using the word PARIS as the standard (50 units per word), matching the ARRL and ITU standard.
Language Extensions
For non-Latin scripts and languages with special characters, we follow ITU regional extensions and established amateur radio practices:
- Arabic: ITU Arabic Morse Code extension standard
- Hebrew: ITU Hebrew Morse Code extension
- Cyrillic / Russian: ITU Cyrillic Morse Code extension
- Spanish: ITU Spanish extensions for Ñ and accented vowels
- French: ITU French extensions for é è à â ê î ô û ç ù
- Filipino / Tagalog: Standard Latin ITU Morse (Filipino uses A–Z)
- Indonesian: Standard Latin ITU Morse (Bahasa Indonesia uses A–Z)
- Hindi: Devanagari Morse mapping per established amateur radio practice
How We Check Our Content
Every Morse code character on this site has been verified against the ITU standard. Our process:
- All character mappings are derived directly from ITU-R M.1677-1
- Audio output is verified against known-correct timing references
- Cross-referenced with ARRL (American Radio Relay League) Morse code tables
- Tested against LCWO (Learn CW Online) character set for amateur radio consistency
- User-reported corrections are reviewed and fixed within 24 hours
Reporting Errors
If you find a Morse code error on any page of this site, please report it immediately at corrections@onlinemorsecode.com. Include the page URL, the character in question, and the correct code. We take accuracy reports seriously and fix confirmed errors as a priority.
Farnsworth and Koch Method Implementation
Our Farnsworth timing feature sends each character at full target speed while increasing the gaps between characters and words. This is the standard method recommended by the ARRL and used by learning tools like LCWO and the G4FON Koch trainer. Our implementation follows the standard Farnsworth multiplier applied to inter-letter and inter-word gaps only, not to the dots and dashes themselves.
The Koch method progression — starting with only 2 characters and adding one at a time when 90% accuracy is reached — follows the approach described by Ludwig Koch (1930s) and popularised in the amateur radio community by Jordan Sherer and the LCWO platform.