Mdformat is an opinionated Markdown formatter that can be used to enforce a consistent style in Markdown files. Mdformat is a Unix-style command-line tool as well as a Python library.
Find out more in the docs.
Install with CommonMark support:
pipx install mdformat
Install with GitHub Flavored Markdown (GFM) support:
pipx install mdformat
pipx inject mdformat mdformat-gfm
Note that GitHub's Markdown renderer supports syntax extensions not included in the GFM specification. For full GitHub support do:
pipx install mdformat
pipx inject mdformat mdformat-gfm mdformat-frontmatter mdformat-footnote mdformat-gfm-alerts
Install with Markedly Structured Text (MyST) support:
pipx install mdformat
pipx inject mdformat mdformat-myst
Format files README.md
and CHANGELOG.md
in place
mdformat README.md CHANGELOG.md
Format .md
files in current working directory recursively
mdformat .
Read Markdown from standard input until EOF
.
Write formatted Markdown to standard output.
mdformat -
mdformat --check README.md CHANGELOG.md
This will not apply any changes to the files. If a file is not properly formatted, the exit code will be non-zero.
foo@bar:~$ mdformat --help
usage: mdformat [-h] [--check] [--version] [--number] [--wrap {keep,no,INTEGER}]
[--end-of-line {lf,crlf,keep}] [--exclude PATTERN]
[paths ...]
CommonMark compliant Markdown formatter
positional arguments:
paths files to format
options:
-h, --help show this help message and exit
--check do not apply changes to files
--version show program's version number and exit
--number apply consecutive numbering to ordered lists
--wrap {keep,no,INTEGER}
paragraph word wrap mode (default: keep)
--end-of-line {lf,crlf,keep}
output file line ending mode (default: lf)
--exclude PATTERN exclude files that match the Unix-style glob pattern (multiple allowed)
The --exclude
option is only available on Python 3.13+.
This README merely provides a quickstart guide for the command line interface. For more information refer to the documentation. Here's a few pointers to get you started:
- Style guide
- Python API usage
- Usage as a pre-commit hook
- Plugin usage
- Plugin development guide
- List of code block formatter plugins
- List of parser extension plugins
- Changelog
Why does mdformat backslash escape special syntax specific to MkDocs / Hugo / Obsidian / GitHub / some other Markdown engine?
Mdformat is a CommonMark formatter. It doesn't have out-of-the-box support for syntax other than what is defined in the CommonMark specification.
The custom syntax that these Markdown engines introduce typically reinvents the meaning of angle brackets, square brackets, parentheses, hash characters — characters that have a special meaning in CommonMark. Mdformat often resorts to backslash escaping these characters to ensure the formatting changes it makes never alters a rendered document.
Additionally some engines, namely MkDocs, do not support CommonMark to begin, so incompatibilities are unavoidable.
Luckily mdformat is extensible by plugins. For many Markdown engines you'll find support by searching the plugin docs or mdformat GitHub topic.
You may also want to consider a documentation engine that adheres to CommonMark as its base syntax e.g. mdBook or Sphinx with Markdown.
Why not use Prettier instead?
Mdformat is pure Python code! Python is pre-installed on macOS and virtually any Linux distribution, meaning that typically little to no additional installations are required to run mdformat. This argument also holds true when using together with pre-commit (also Python). Prettier on the other hand requires Node.js/npm.
Prettier suffers from
numerous
bugs,
many of which cause changes in Markdown AST and rendered HTML.
Many of these bugs are a consequence of using
remark-parse
v8.x as Markdown parser which,
according to the author themselves,
is inferior to markdown-it used by mdformat.
remark-parse
v9.x is advertised as CommonMark compliant
and presumably would fix many of the issues,
but is not used by Prettier (v3.3.3) yet.
Prettier (v3.3.3), being able to format many languages other than Markdown, is a large package with 73 direct dependencies (mdformat only has one in Python 3.11+). This can be a disadvantage in many environments, one example being size optimized Docker images.
Mdformat's parser extension plugin API allows not only customization of the Markdown specification in use, but also advanced features like automatic table of contents generation. Also provided is a code formatter plugin API enabling integration of embedded code formatting for any programming language.
Nope, the logo is actually pretty great – you're terrible. The logo is more a piece of art than a logo anyways, depicting the horrors of poorly formatted text documents. I made it myself!
That said, if you have any graphic design skills and want to contribute a revised version, a PR is more than welcome 😄.