If you searched for the ITU-R M.1677-1 international Morse code PDF, you want the document that actually defines the code — not another decorative alphabet poster. Recommendation ITU-R M.1677-1 (October 2009) is that document. This page explains what it contains, how the timing ratios work, and how to check that a web chart matches the table. Download the official PDF from the ITU. Then use our alphabet chart and translator as practice tools that follow the same International Morse mappings.
What M.1677-1 is (and is not)
The International Telecommunication Union publishes radiocommunication recommendations. ITU-R M.1677-1 is titled “International Morse code.” It lists the characters, the procedural signals, and the relative lengths of dots, dashes, and spaces. Administrations and amateur services treat it as the global reference when they say “Morse” without a qualifier.
It is not a training syllabus. It does not tell you to learn Koch or Farnsworth. It does not rank translators. It does not include American railroad Morse. If a blog mixes those jobs, you end up practicing the wrong L or the wrong C and blaming your ears.
Revision 1 (2009) superseded the earlier M.1677 text. Unless you are writing radio history, you want the -1 PDF, not a scan of a 19th-century continental table. The ITU page is the download: Recommendation ITU-R M.1677-1. Wikipedia’s Morse code article summarizes the same timing for readers who want a secondary overview.
The timing ratios that make charts honest
Learners argue about “how long is a dash” because apps invent their own feel. The recommendation is boring on purpose:
- Dot = 1 unit
- Dash = 3 units
- Gap inside a character (dot to dash, dash to dot) = 1 unit
- Gap between characters = 3 units
- Gap between words = 7 units
Those ratios are why Farnsworth spacing is legal pedagogy: you keep the 1:3 shapes inside each letter and stretch only the 3-unit and 7-unit gaps so your brain hears a character as one lump. If an app lengthens the dash to “sound nicer,” it is no longer teaching M.1677-1 Morse. Check a known letter — T is one dash, E is one dot, A is dot-dash — on the interactive alphabet and compare the PDF table.
Letters, figures, and punctuation in the table
The recommendation’s annex is the character table. A–Z and 0–9 are the everyday set. Figures are five elements each (1 is .----, 0 is -----). Punctuation and prosigns occupy the rest of the page. If a “complete Morse chart” on the internet adds emoji, extra accented letters, or railroad-only symbols without a label, it has left the ITU table.
Accented letters used in some European services appear in related material; do not assume they are in every app. For English practice, stay inside the A–Z / 0–9 block plus the punctuation you actually send. Our International vs American Morse post lists the letters that diverge if you are reading Civil War-era tape.
How to verify a website against the PDF
Open the official PDF. Pick five characters that trip people up: C, Q, Y, 7, and the period. Check this site’s chart and any other tool you use. If C is not -.-. or Q is not --.-, stop practicing there. Then send the word PARIS on the translator and confirm you hear letter spacing, not a smear. PARIS is the traditional timing word because it is 50 units at standard spacing — a fact trainers use, not a fact the ITU invented for tourism.
Do not treat a PNG of the ITU cover as a substitute for the table. Cover art ranks. The annex is the product.
What this page will not do
We will not host a re-typeset copy of the entire recommendation. That document is ITU’s. We will not claim affiliation. We will not hide American Morse inside an “international” heading. The homepage translator is for converting text you type. The alphabet is for looking up one character. The PDF is for citing the standard when someone says your dash is too short.
If you came here from a search for “ITU Morse PDF,” download it first, then come back for practice. The standard is short. The practice is the long part.