mor.js is a pure JavaScript library for encoding/decoding Morse code messages that supports extensible characters and encoding output.

The library provides a very simple API that exposes the easy encoding/decoding functionality while only exposing a single global variable (morjs). The predefined Morse alphabet is based on the ITU but mor.js allows this to be easily extended by adding and/or modifying characters.


Install using the package manager for your desired environment(s):

# for node.js:
$ npm install morjs
# OR; for the browser:
$ bower install morjs

This library has no dependencies on any other library.


The API has been completely redesigned to simplify encoding and decoding Morse code messages by simply passing a string to the encode and decode functions respectively.

It's important to note that some characters are encoded to the same Morse code sequence (mainly outside of the normal alphabet). This also means that, when decoding such messages, the original character is not guaranteed to be matched unless it's the first using that sequence. This is not a limitation of this library but of the Morse code language itself which did not guarantee uniqueness.

Both of which also accept an optional options parameter which can currently contain the following (all of which are optional themselves):

Option Description Default
mode Mode to be used to encode/decode the message "compact"

encode(message[, options])

Encodes the message parameter using the Morse code.

console.log(morjs.encode('SOS', {mode: 'simple'})); // "... --- ..."

decode(message[, options])

Decodes the encoded Morse code message parameter.

console.log(morjs.decode('... --- ...', {mode: 'simple'})); // "SOS"



This is a hash of default values to be applied to the optional options parameter and exposed to allow you to override any of them.

morjs.defaults.mode = 'simple';

console.log(morjs.encode('SOS')); // "... --- ..."


A simple map of Unicode characters and their corresponding patterns, which are used when encoding and decoding messages. A pattern is a series of "S" and "L" characters representing short and long respectively.

The characters are too many to list here but you can find them easily in the source code or when inspecting this value.

Adding support for a new character couldn't be easier. In the following example support for the lambda character is added using a made-up pattern:

morjs.chars['\u039B'] = 'LLLLLSSSSS';

console.log(morjs.encode('\u039B', {mode: 'simple'})); // "-----....."


Modes are key to parsing both encoded and decoded messages as they contain strings used to find and replace patterns in the message. Some of these strings are used to build regular expressions, so it's recommended to familiarized yourself with the usage of modes before creating any custom ones, just so you know on which you need to escape any RegExp special characters.

Here's a list of the built in modes:

Adding a new mode is as simple as the following: = {
  charSpacer:   '',
  letterSpacer: ' ',
  longString:   'F',
  shortString:  'O',
  wordSpacer:   '   '

var options = {mode: 'foo'};

console.log(morjs.encode('SOS', options));         // "OOO FFF OOO"
console.log(morjs.decode('OOO FFF OOO', options)); // "SOS"



Returns morjs in a no-conflict state, reallocating the morjs global variable name to its previous owner, where possible.

This is really just intended for use within a browser.

<script src="/path/to/conflict-lib.js"></script>
<script src="/path/to/mor.min.js"></script>
  var morjsNC = morjs.noConflict();
  // Conflicting lib works again and use morjsNC for this library onwards...


The current version of morjs.

console.log(morjs.VERSION); // "1.1.0"


Version 1.1.0

View historical changes


If you have any problems with this library or would like to see changes currently in development you can do so here.


If you want to contribute, you're a legend! Information on how you can do so can be found in We want your suggestions and pull requests!

A list of mor.js contributors can be found in


Copyright © 2014 Alasdair Mercer

See for more information on our MIT license.