Top 11 JavaScript Markdown Libraries

Markdown is a lightweight and easy-to-read markup language that allows users to format plain text content without the complexities of HTML or other markup languages. It was created by John Gruber and Aaron Swartz in 2004 with the goal of making writing for the web more accessible and efficient.

To integrate Markdown into a web app using JavaScript, you can leverage existing JavaScript Markdown libraries which provide functionalities to parse, render, and manipulate Markdown text. Here are some of the widely used:

  • Marked (30.1k ⭐) — One of the most popular and straightforward Markdown parsers for JavaScript, also available as a CLI tool. It allows you to convert Markdown to HTML and includes support for GitHub-flavored Markdown.

  • markdown-it (15.7k ⭐) — A Markdown parser that follows the CommonMark specification and supports extensions and plugins. It is written in JavaScript and can be used in node.js or browser environments. It is fast, easy to extend, and safe by default.

  • MDX (15.5k ⭐) — A library that allows you to use JSX, a syntax extension of JavaScript that lets you write HTML-like elements, in Markdown content. MDX enables you to import components, such as interactive charts or alerts, and embed them within Markdown. This makes writing long-form content with components a blast.

  • mdx-deck (11.1k ⭐) — A library based on MDX that allows you to create presentations using Markdown and React components. You can write your slides in a single MDX file and separate them with ---. You can also import and use any React component in your slides, as well as customize the theme and layout of your presentation.

  • react-markdown (10.8k ⭐) — A React component that safely renders Markdown into HTML. It is built and maintained by UnifiedJS, the same folks behind RemarkJS and RehypeJS. It uses a syntax tree to build the virtual DOM, which allows for updating only the changing DOM instead of completely overwriting.

  • Turndown (7k ⭐) — Different from typical Markdown parsers; it converts HTML to Markdown instead of the other way around. It’s useful when you want to convert HTML content back to Markdown format. Turndown uses a group of regular expressions to escape potential Markdown syntax.

  • remark (6.5k ⭐) — A popular tool that transforms Markdown with plugins. These plugins can inspect and change your markup. You can use remark on the server, the client, CLIs, deno, etc1. It is part of the unified collective, which brings together organisations that work with content as structured data.

  • Markdoc (6.4k ⭐) — A powerful, flexible, Markdown-based authoring framework. Markdoc allows you to create custom documentation sites and experiences using Markdown syntax and plugins. You can use Markdoc to render your content into HTML, React, or other formats.

  • remarkable (5.5k ⭐) — A high-speed Markdown parser. Remarkable allows you to convert markdown text into HTML with full CommonMark and GFM support. You can also customize the syntax rules and rendering options.

  • textlint (2.6k ⭐) — A pluggable natural language linter for text and Markdown. textlint allows you to check and fix your writing errors based on custom rules. You can use textlint to improve your writing quality, style, and consistency.

  • mdsvex (1.9k ⭐) — A Markdown preprocessor for Svelte components. MDsveX allows you to use Svelte components in your markdown, or Markdown in your Svelte components. It is similar to MDX, but for Svelte.

Why Markdown is popular

Markdown’s syntax is simple and intuitive, using plain text and special characters to indicate various formatting elements such as headings, lists, links, and more. Markdown has gained immense popularity for several reasons:

  • Simplicity: Markdown’s syntax is straightforward and easy to learn, making it accessible to both technical and non-technical users.
  • Readability: Markdown files are human-readable and don’t clutter the text with excessive markup tags, enhancing the focus on the content.
  • Widespread adoption: Markdown is widely supported across various platforms, blogging systems, and content management systems (CMS), making it a portable and versatile choice for writing content.
  • Version control friendly: Since Markdown files are plain text, they play well with version control systems like Git, allowing for easy collaboration and tracking changes in text-based content.
  • Web friendly: Markdown can be easily converted to HTML, enabling users to publish content on the web without having to write raw HTML code.

Difference between flavors of markdown

There is no official standard for Markdown syntax, and different implementations may have different features or behaviors. These variations are called flavors of Markdown. Some of the most common flavors of Markdown are:

  • CommonMark: A specification and reference implementation for Markdown that aims to provide a consistent and unambiguous syntax.
  • GitHub Flavored Markdown (GFM): A version of Markdown that is used by GitHub for comments, issues, pull requests, wikis, etc. It adds some extensions to CommonMark, such as tables, task lists, strikethrough, etc.
  • MultiMarkdown: A version of Markdown that adds features for cross-referencing, footnotes, tables, metadata, math expressions, etc.
  • Markdown Extra: A version of Markdown that adds features for tables, fenced code blocks, definition lists, footnotes, etc.

There are many other flavors of Markdown, such as MDX, MDsveX, Markdoc, Remarkable, etc. Each flavor may have its own syntax rules and options.

Markdown vs HTML

Markdown and HTML are both markup languages that can be used to create formatted text documents. However, they have some differences in terms of syntax, features, and usage:

  • Syntax: Markdown uses a simple and intuitive syntax that consists of symbols and characters, such as # for headings, * for emphasis, [ ] for links, etc. HTML uses a more complex and verbose syntax that consists of tags and attributes, such as <h1> for headings, <em> for emphasis, <a> for links, etc.

  • Features: Markdown supports a limited set of formatting elements, such as headings, lists, code blocks, images, etc. HTML supports a much wider range of formatting elements, such as tables, forms, scripts, styles, etc. Markdown can be extended with plugins or converted to HTML to achieve more features. HTML can also be combined with other languages, such as CSS and JavaScript, to enhance the presentation and functionality.

  • Usage: Markdown is mainly used for writing plain text content that can be easily read and edited by humans. It is often used for creating readme files, blog posts, documentation, notes, etc. HTML is mainly used for publishing structured content that can be rendered by browsers. It is often used for creating web pages, applications, newsletters, etc.

Here is an original example of Markdown and its equivalent HTML:

# Heading 1

## Heading 2

This is a paragraph with some **bold text** and *italic text*.

- Item 1
- Item 2
- Item 3

[Visit byby.dev](https://byby.dev)

HTML:

<h1>Heading 1</h1>
<h2>Heading 2</h2>
<p>This is a paragraph with some <strong>bold text</strong> and <em>italic text</em>.</p>
<ul>
  <li>Item 1</li>
  <li>Item 2</li>
  <li>Item 3</li>
</ul>
<p><a href="https://byby.dev">Visit byby.dev</a></p>