Markdown Flavors Comparison

A living comparison of syntax extensions across popular Markdown flavors and parsers.

About This Project

This comparison helps developers, technical writers, and documentation maintainers understand which Markdown features are supported by different parsers and platforms. Whether you're choosing a Markdown flavor for a new project or migrating documentation, this resource provides a quick reference.

Original Work

This project builds upon the excellent work by @vimtaai from their markdown-flavors.md comparison (2021). We've updated it for 2025 with modern flavors, new features, and community contributions.Completed collaboratively with Claude Sonnet 4.5 as a development partner and technical consultant.

Note: The original comparison included ExtraMark, a student project that has been archived here for historical reference.

Feature Support Matrix

Flavor	Superscript	Subscript	Strikethrough	Insertion	Highlight	Footnote	Task List	Table	Abbreviation	Definition List	Alerts	Callout/Admonition	Wikilinks	Mermaid	Math	Math Block	Emoji
CommonMark	❌	❌	❌	❌	❌	❌	❌	✅	❌	❌	❌	❌	❌	❌	❌	❌	❌
GitHub (GFM)	❌	❌	~~text~~	❌	❌	❌	- [ ]	✅	❌	❌	> [!NOTE]	❌	❌	✅	❌	$$...$$	:emoji:
GitLab	❌	❌	~~text~~	{+text+}	❌	[^1]	- [ ]	✅	❌	❌	❌	❌	❌	✅	$...$	```math	:emoji:
Obsidian	❌	~text~	~~text~~	❌	==text==	[^1]	- [ ]	✅	❌	❌	> [!note]	✅	[[page]]	✅	$...$	$$...$$	:emoji:
Discord	❌	❌	~~text~~	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	:emoji:
Pandoc	^text^	~text~	~~text~~	❌	❌	[^1]	❌	✅	*[...]:	:	❌	::: info	❌	❌	$...$	$$...$$	:emoji:
MultiMarkdown	^text^	~text~	{--text--}	{++text++}	{==text==}	[^1]	❌	✅	*[...]:	:	❌	❌	❌	❌	\\(...\\)	\\[...\\]	❌
Kramdown	❌	❌	❌	❌	❌	[^1]	❌	✅	*[...]:	:	❌	❌	❌	❌	$$...$$	$$...$$	❌
Python-Markdown	^text^ *	~text~ *	~~text~~ *	❌	==text== *	[^1]	- [ ] *	✅	*[...]: *	: *	❌	!!! note *	[[page]] *	❌	❌	❌	:emoji: *
Marked.js	❌	❌	~~text~~ *	❌	❌	❌	- [ ] *	✅	❌	❌	❌	❌	❌	❌	❌	❌	:emoji: *
R Markdown	^text^	~text~	~~text~~	❌	❌	[^1]	❌	✅	❌	❌	❌	::: callout	❌	✅	$...$	$$...$$	:emoji:
MDX	❌	❌	~~text~~ *	❌	❌	❌	❌	✅	❌	❌	❌	❌	❌	❌	❌	❌	❌
Quarto	^text^	~text~	~~text~~	❌	❌	[^1]	- [ ]	✅	❌	:	❌	::: callout	❌	✅	$...$	$$...$$	:emoji:
Markdown Extra	❌	❌	❌	❌	❌	[^1]	❌	✅	*[...]:	:	❌	❌	❌	❌	❌	❌	❌

Legend:

• ✅ = Supported natively
• syntax = Syntax example
• ❌ = Not supported
• * = Requires extension/plugin

Feature Descriptions

Text Formatting Extensions

• Superscript: Text displayed above the normal line (e.g., x^2^)
• Subscript: Text displayed below the normal line (e.g., H2O)
• Strikethrough: Text with a line through it (deleted/deprecated content)
• Insertion: Markup for inserted/added content (often used with CriticMarkup)
• Highlight: Background highlighting for emphasis

Semantic Syntax Features

These features provide meaningful structure for accessibility, AI parsing, and semantic HTML:

• Abbreviation: Define abbreviations with *[HTML]: Hypertext Markup Language - improves accessibility and helps readers understand acronyms
• Definition List: Key-value pairs using : syntax - useful for glossaries, term definitions, and structured metadata
• Alerts (GitHub-specific): Styled notification blocks using > [!NOTE], > [!WARNING], > [!IMPORTANT] syntax - similar to callouts but with standardized types
• Callout/Admonition: Styled blocks for notes, warnings, tips using various syntaxes (::: note, > [!note], !!! note) - helps organize information by importance/type

Document Structure

• Footnote: Reference notes at the bottom of the document
• Task List: Interactive checkboxes for to-do items
• Table: Structured tabular data

Advanced Features

• Wikilinks: Internal document linking with [[page]] syntax
• Mermaid: Diagram and flowchart generation
• Math: Inline mathematical expressions (LaTeX)
• Math Block: Display mathematical equations (LaTeX blocks)
• Emoji: Support for :emoji: syntax or Unicode

Flavor-Specific Notes

CommonMark

The base specification that many flavors extend. Intentionally minimal to ensure broad compatibility.

GitHub Flavored Markdown (GFM)

GitHub's implementation, widely used in README files, issues, and pull requests. Added support for math blocks in 2022 and Alerts in 2023.

Obsidian

Optimized for knowledge management with strong support for internal linking, callouts, and community plugins that extend functionality.

Python-Markdown

Highly extensible through its extension system. Most advanced features require installing specific extensions.

Pandoc

Swiss-army knife of document conversion. Extensive feature support for academic and technical writing.

Quarto

Modern scientific and technical publishing system built on Pandoc, popular in data science.

MDX

Allows JSX components in Markdown, primarily used with React-based documentation sites.

Contributing

We welcome contributions! This is a living document that should reflect the current state of Markdown parsers.

How to Contribute

1. Fork this repository
2. Add or update flavor information in both:
   • README.md (the comparison table)
   • markdown-flavors.csv (the data file)
3. Include in your PR:
   • Link to official documentation
   • Version number (if applicable)
   • Date tested
4. Submit a pull request

Guidelines

• Test features yourself or provide documentation links
• Include version numbers for parsers (e.g., "Marked.js v12.0.0")
• Note if a feature requires plugins/extensions
• Be specific about syntax variations
• Update both the table and CSV file

Data Format

The machine-readable data is available in markdown-flavors.csv for programmatic access.

Version History

• 2025-01-22: Added GitHub Alerts, Abbreviations, Definition Lists; reorganized features into semantic categories (thanks to @saeris for terminology feedback)
• 2025-01: Updated comparison with modern flavors (Obsidian, Quarto, MDX), new features (callouts, wikilinks, emoji)
• 2021-06: Original comparison by @vimtaai

Related Resources

• CommonMark Spec
• GitHub Flavored Markdown Spec
• Pandoc Markdown
• Markdown Guide

License

This comparison is released under CC0 1.0 Universal (Public Domain). The original work by vimtaai was also released under CC0.

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Maintainers: Looking for maintainers to help keep this up-to-date. Open an issue if interested!

Last Updated: January 22, 2025