marked

What is marked?

The marked npm package is a markdown parser and compiler built for speed. It converts markdown syntax to HTML, and it is designed to be as extensible and fast as possible.

What are marked's main functionalities?

Markdown Parsing

This feature allows you to parse markdown text and convert it to HTML. The code sample shows how to use marked to convert a simple markdown string into HTML.

const marked = require('marked');
console.log(marked('# Marked in Node.js\n\nRendered by **marked**.'));

Options Customization

This feature allows you to customize the behavior of the marked parser by setting options such as GitHub Flavored Markdown (GFM), breaks, pedantic, sanitize, smart lists, and smartypants.

const marked = require('marked');
marked.setOptions({
  renderer: new marked.Renderer(),
  gfm: true,
  breaks: false,
  pedantic: false,
  sanitize: false,
  smartLists: true,
  smartypants: false
});
console.log(marked('I am using __markdown__.'));

Synchronous Parsing

This feature allows you to parse markdown synchronously, which is useful when you don't need to handle asynchronous operations.

const marked = require('marked');
const html = marked('## Synchronous markdown to HTML');
console.log(html);

Asynchronous Parsing

This feature allows you to parse markdown asynchronously, which can be useful when dealing with file systems or network requests.

const marked = require('marked');
marked('# Asynchronous markdown to HTML', function(err, content) {
  if (err) throw err;
  console.log(content);
});

Lexer and Parser

This feature exposes the lexer and parser, allowing you to generate tokens from markdown and then parse those tokens into HTML. This can be useful for advanced use-cases where you need to manipulate the tokens before parsing.

const marked = require('marked');
const tokens = marked.lexer('# Lexing markdown');
console.log(tokens);
const html = marked.parser(tokens);
console.log(html);

Other packages similar to marked

remarkable

Remarkable is an npm package that offers similar markdown parsing and rendering capabilities. It provides a full-featured markdown parser and compiler, and it emphasizes extensibility and performance, much like marked.

showdown

Showdown is another markdown to HTML converter that can be used both in the browser and on the server. It has a similar feature set to marked but also includes extensions which allow for additional syntax and features beyond the standard markdown.

markdown-it

Markdown-it is a modern markdown parser with a focus on speed and extensibility. It supports the CommonMark specification and has a similar feature set to marked, but it also includes a plugin system for extending its capabilities.

README

marked

A full-featured markdown parser and compiler, written in javascript. Built for speed.

Install

npm install marked --save

Usage

Minimal usage:

console.log(marked('I am using __markdown__.'));
// Outputs: <p>I am using <i>markdown</i>.</p>

Example using all options:

// Set default options except highlight which has no default
marked.setOptions({
  gfm: true,
  highlight: function (code, lang, callback) {
    pygmentize({ lang: lang, format: 'html' }, code, function (err, result) {
      if (err) return callback(err);
      callback(null, result.toString());
    });
  },
  tables: true,
  breaks: false,
  pedantic: false,
  sanitize: true,
  smartLists: true,
  smartypants: false,
  langPrefix: 'lang-'
});

// Using async version of marked
marked('I am using __markdown__.', function (err, content) {
  if (err) throw err;
  console.log(content);
});

marked(markdownString, [options], [callback])

markdownString

Type: String

String of markdown source to be compiled.

options

Type: Object

Hash of options. Can also be set using the marked.setOptions method as seen above.

callback

Type: Function

Function called when the markdownString has been fully parsed when using async highlighting. If the options argument is omitted, this can be used as the second argument as seen above:

Options

gfm

Type: Boolean Default: true

Enable GitHub flavored markdown.

highlight

Type: Function

A function to highlight code blocks. The function takes three arguments: code, lang, and callback. The above example uses async highlighting with node-pygementize-bundled, and here is a synchronous example using highlight.js which doesn't require the callback argument:

marked.setOptions({
  highlight: function (code, lang) {
    return hljs.highlightAuto(lang, code).value;
  }
});

highlight arguments

code

Type: String

The section of code to pass to the highlighter.

lang

Type: String

The programming language specified in the code block.

callback

Type: String

The callback function to call when using an async highlighter.

tables

Type: Boolean Default: true

Enable GFM tables. This option requires the gfm option to be true.

breaks

Type: Boolean Default: false

Enable GFM line breaks. This option requires the gfm option to be true.

pedantic

Type: Boolean Default: false

Conform to obscure parts of markdown.pl as much as possible. Don't fix any of the original markdown bugs or poor behavior.

sanitize

Type: Boolean Default: false

Sanitize the output. Ignore any HTML that has been input.

smartLists

Type: Boolean Default: true

Use smarter list behavior than the original markdown. May eventually be default with the old behavior moved into pedantic.

smartypants

Type: Boolean Default: false

Use "smart" typograhic punctuation for things like quotes and dashes.

langPrefix

Type: String Default: lang-

Set the prefix for code block classes.

Access to lexer and parser

You also have direct access to the lexer and parser if you so desire.

var tokens = marked.lexer(text, options);
console.log(marked.parser(tokens));

var lexer = new marked.Lexer(options);
var tokens = lexer.lex(text);
console.log(tokens);
console.log(lexer.rules);

CLI

$ marked -o hello.html
hello world
^D
$ cat hello.html
<p>hello world</p>

Benchmarks

node v0.4.x

$ node test --bench
marked completed in 12071ms.
showdown (reuse converter) completed in 27387ms.
showdown (new converter) completed in 75617ms.
markdown-js completed in 70069ms.

node v0.6.x

$ node test --bench
marked completed in 6448ms.
marked (gfm) completed in 7357ms.
marked (pedantic) completed in 6092ms.
discount completed in 7314ms.
showdown (reuse converter) completed in 16018ms.
showdown (new converter) completed in 18234ms.
markdown-js completed in 24270ms.

Marked is now faster than Discount, which is written in C.

For those feeling skeptical: These benchmarks run the entire markdown test suite 1000 times. The test suite tests every feature. It doesn't cater to specific aspects.

node v0.8.x

$ node test --bench
marked completed in 3411ms.
marked (gfm) completed in 3727ms.
marked (pedantic) completed in 3201ms.
robotskirt completed in 808ms.
showdown (reuse converter) completed in 11954ms.
showdown (new converter) completed in 17774ms.
markdown-js completed in 17191ms.

Another Javascript Markdown Parser

The point of marked was to create a markdown compiler where it was possible to frequently parse huge chunks of markdown without having to worry about caching the compiled output somehow...or blocking for an unnecesarily long time.

marked is very concise and still implements all markdown features. It is also now fully compatible with the client-side.

marked more or less passes the official markdown test suite in its entirety. This is important because a surprising number of markdown compilers cannot pass more than a few tests. It was very difficult to get marked as compliant as it is. It could have cut corners in several areas for the sake of performance, but did not in order to be exactly what you expect in terms of a markdown rendering. In fact, this is why marked could be considered at a disadvantage in the benchmarks above.

Along with implementing every markdown feature, marked also implements GFM features.

$ node
> require('marked').lexer('> i am using marked.')
[ { type: 'blockquote_start' },
  { type: 'paragraph',
    text: 'i am using marked.' },
  { type: 'blockquote_end' },
  links: {} ]

Running Tests & Contributing

If you want to submit a pull request, make sure your changes pass the test suite. If you're adding a new feature, be sure to add your own test.

The marked test suite is set up slightly strangely: test/new is for all tests that are not part of the original markdown.pl test suite (this is where your test should go if you make one). test/original is only for the original markdown.pl tests. test/tests houses both types of tests after they have been combined and moved/generated by running node test --fix or marked --test --fix.

In other words, if you have a test to add, add it to test/new/ and then regenerate the tests with node test --fix. Commit the result. If your test uses a certain feature, for example, maybe it assumes GFM is not enabled, you can add .nogfm to the filename. So, my-test.text becomes my-test.nogfm.text. You can do this with any marked option. Say you want line breaks and smartypants enabled, your filename should be: my-test.breaks.smartypants.text.

To run the tests:

cd marked/
node test

Contribution and License Agreement

If you contribute code to marked, you are implicitly allowing your code to be distributed under the MIT license. You are also implicitly verifying that all code is your original work. </legalese>

License

Copyright (c) 2011-2013, Christopher Jeffrey. (MIT License)

See LICENSE for more info.