oremb / markdown-it

Markdown parser, done right. 100% CommonMark support, extensions, syntax plugins & high speed

markdown-it

Markdown parser done right. Fast and easy to extend.

Live demo

• Follows the CommonMark spec + adds syntax extensions & sugar (URL autolinking, typographer).
• Configurable syntax! You can add new rules and even replace existing ones.
• High speed.
• Safe by default.
• Community-written plugins and other packages on npm.

Table of content

• markdown-it
  • Install
  • Usage examples
    • Simple
    • Init with presets and options
    • Plugins load
    • Syntax highlighting
    • Linkify
  • API
  • Syntax extensions
    • Manage rules
  • Benchmark
  • Support markdown-it
  • Authors
  • References / Thanks

Install

node.js & bower:

npm install markdown-it --save
bower install markdown-it --save

browser (CDN):

• jsDeliver CDN
• cdnjs.com CDN

Usage examples

See also:

• API documentation - for more info and examples.
• Development info - for plugins writers.

Simple

// node.js, "classic" way:
var MarkdownIt = require('markdown-it'),
    md = new MarkdownIt();
var result = md.render('# markdown-it rulezz!');

// node.js, the same, but with sugar:
var md = require('markdown-it')();
var result = md.render('# markdown-it rulezz!');

// browser without AMD, added to "window" on script load
// Note, there is no dash in "markdownit".
var md = window.markdownit();
var result = md.render('# markdown-it rulezz!');

Single line rendering, without paragraph wrap:

var md = require('markdown-it')();
var result = md.renderInline('__markdown-it__ rulezz!');

Init with presets and options

(*) presets define combinations of active rules and options. Can be "commonmark", "zero" or "default" (if skipped). See API docs for more details.

// commonmark mode
var md = require('markdown-it')('commonmark');

// default mode
var md = require('markdown-it')();

// enable everything
var md = require('markdown-it')({
  html: true,
  linkify: true,
  typographer: true
});

// full options list (defaults)
var md = require('markdown-it')({
  html:         false,        // Enable HTML tags in source
  xhtmlOut:     false,        // Use '/' to close single tags (<br />).
                              // This is only for full CommonMark compatibility.
  breaks:       false,        // Convert '\n' in paragraphs into <br>
  langPrefix:   'language-',  // CSS language prefix for fenced blocks. Can be
                              // useful for external highlighters.
  linkify:      false,        // Autoconvert URL-like text to links

  // Enable some language-neutral replacement + quotes beautification
  typographer:  false,

  // Double + single quotes replacement pairs, when typographer enabled,
  // and smartquotes on. Could be either a String or an Array.
  //
  // For example, you can use '«»„“' for Russian, '„“‚‘' for German,
  // and ['«\xA0', '\xA0»', '‹\xA0', '\xA0›'] for French (including nbsp).
  quotes: '“”‘’',

  // Highlighter function. Should return escaped HTML,
  // or '' if the source string is not changed and should be escaped externally.
  // If result starts with <pre... internal wrapper is skipped.
  highlight: function (/*str, lang*/) { return ''; }
});

Plugins load

var md = require('markdown-it')()
            .use(plugin1)
            .use(plugin2, opts, ...)
            .use(plugin3);

Syntax highlighting

Apply syntax highlighting to fenced code blocks with the highlight option:

var hljs = require('highlight.js'); // https://highlightjs.org/

// Actual default values
var md = require('markdown-it')({
  highlight: function (str, lang) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return hljs.highlight(lang, str).value;
      } catch (__) {}
    }

    return ''; // use external default escaping
  }
});

Or with full wrapper override (if you need assign class to <pre>):

var hljs = require('highlight.js'); // https://highlightjs.org/

// Actual default values
var md = require('markdown-it')({
  highlight: function (str, lang) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return '<pre class="hljs"><code>' +
               hljs.highlight(lang, str, true).value +
               '</code></pre>';
      } catch (__) {}
    }

    return '<pre class="hljs"><code>' + md.utils.escapeHtml(str) + '</code></pre>';
  }
});

Linkify

linkify: true uses linkify-it. To configure linkify-it, access the linkify instance through md.linkify:

md.linkify.tlds('.py', false);  // disables .py as top level domain

API

API documentation

If you are going to write plugins - take a look at Development info.

Syntax extensions

Embedded (enabled by default):

• Tables (GFM)
• Strikethrough (GFM)

Via plugins:

• subscript
• superscript
• footnote
• definition list
• abbreviation
• emoji
• custom container
• insert
• mark
• ... and others

Manage rules

By default all rules are enabled, but can be restricted by options. On plugin load all its rules are enabled automatically.

// Activate/deactivate rules, with curring
var md = require('markdown-it')()
            .disable([ 'link', 'image' ])
            .enable([ 'link' ])
            .enable('image');

// Enable everything
md = require('markdown-it')({
  html: true,
  linkify: true,
  typographer: true,
});

Benchmark

Here is the result of readme parse at MB Pro Retina 2013 (2.4 GHz):

make benchmark-deps
benchmark/benchmark.js readme

Selected samples: (1 of 28)
 > README

Sample: README.md (7774 bytes)
 > commonmark-reference x 1,222 ops/sec ±0.96% (97 runs sampled)
 > current x 743 ops/sec ±0.84% (97 runs sampled)
 > current-commonmark x 1,568 ops/sec ±0.84% (98 runs sampled)
 > marked x 1,587 ops/sec ±4.31% (93 runs sampled)

Note. CommonMark version runs with simplified link normalizers for more "honest" compare. Difference is ~ 1.5x.

As you can see, markdown-it doesn't pay with speed for it's flexibility. Slowdown of "full" version caused by additional features not available in other implementations.

Support markdown-it

You can support this project via Tidelift subscription.

Authors

• Alex Kocharin github/rlidwka
• Vitaly Puzrin github/puzrin

markdown-it is the result of the decision of the authors who contributed to 99% of the Remarkable code to move to a project with the same authorship but new leadership (Vitaly and Alex). It's not a fork.

References / Thanks

Big thanks to John MacFarlane for his work on the CommonMark spec and reference implementations. His work saved us a lot of time during this project's development.

Related Links:

• https://github.com/jgm/CommonMark - reference CommonMark implementations in C & JS, also contains latest spec & online demo.
• http://talk.commonmark.org - CommonMark forum, good place to collaborate developers' efforts.

Ports

• motion-markdown-it - Ruby/RubyMotion