Morse code API & data

Schema

{
  "morseMap": {
    "A": ".-",
    "B": "-...",
    "...": "...",
    "0": "-----",
    "1": ".----",
    "...": "...",
    ".": ".-.-.-",
    "@": ".--.-."
  },
  "extendedMap": {
    "É": "..-..",
    "Ñ": "--.--"
  },
  "phrases": [
    ["sos", "SOS"],
    ["mayday", "MAYDAY"],
    ["i-love-you", "I LOVE YOU"]
  ]
}

• morseMap: canonical mapping. Keys are uppercase letters / digits / exact punctuation.
• extendedMap: letters outside the basic set — É, the one accented letter in ITU-R M.1677-1, and Ñ, the Spanish addition. Kept separate so a strict ITU implementation can ignore it; merge it over morseMap if you want them.
• phrases: array of [slug, PHRASE] pairs (uppercase phrase).

Quick examples

JavaScript (browser or Node)

const data = await fetch("https://morsecodegenerator.com/morse.json").then(r => r.json());
const map = data.morseMap;

function textToMorse(text) {
  return text.toUpperCase().split(/\s+/).filter(Boolean)
    .map(w => w.split("").map(c => map[c] || "").filter(Boolean).join(" "))
    .join(" / ");
}

console.log(textToMorse("Hello world")); // .... . .-.. .-.. --- / .-- --- .-. .-.. -..

Python

import json, urllib.request
data = json.load(urllib.request.urlopen("https://morsecodegenerator.com/morse.json"))
m = data["morseMap"]

def text_to_morse(s):
    return " / ".join(
        " ".join(m[c] for c in w if c in m)
        for w in s.upper().split()
    )

print(text_to_morse("Hello world"))

cURL

curl https://morsecodegenerator.com/morse.json | jq .morseMap.A

What you get, exactly

The file is 54 characters and 56 phrases — about 2.0 KB of JSON, small enough to fetch once at start-up and keep in memory. It is a static file on a CDN, not a service: there is no key, no quota and no rate limit, and nothing about your request is logged back to you.

• Every pattern is unique. No two characters share a dot-dash sequence, so you can build a reverse map straight from morseMap and decode with it.
• Keys are uppercase. Upper-case your input before looking it up; lowercase keys do not exist in the file.
• Unmapped characters. Accented letters, ¿, ¡, #, * and emoji are not in the map. Decide deliberately whether to skip them or report them — silently dropping characters is the most common bug in Morse converters.
• Not included. Prosigns, Q-codes and CW abbreviations are not in this file; they are published as pages at /prosigns/, /q-codes/ and /abbreviations/.

Caching and stability

Responses are sent with Cache-Control: public, max-age=300, s-maxage=86400, stale-while-revalidate=604800, so browsers hold a copy for five minutes and the CDN for a day. Please cache on your side too rather than fetching the file on every conversion.

The character map follows Recommendation ITU-R M.1677-1 and is not going to change: codes are only ever added, never redefined, and morseMap and phrases keep their shape. The same file powers every tool on this site, so if a pattern here were wrong the site would be wrong with it.

Conventions

• Letter separator inside a word: " " (single space).
• Word separator: " / " (space-slash-space).
• Standard PARIS WPM timing: 1 unit ms = 1200 / WPM.
• Standard tone: 600–700 Hz (pleasant for ear training).