---
id: rumdl
version: "0.2.55"
license: MIT
license_treatment: permissive
maintenance: active
---

# rumdl — A fast Markdown linter written in Rust

License: permissive · Maintenance: active · Downloads: 832.2K/mo

## What it is and what it does

rumdl is a Markdown linter and formatter written in Rust and distributed as a Python package. It scans Markdown files for style and consistency issues across 82 built-in rules, supports multiple Markdown flavors (GFM, MkDocs, MDX, Quarto, MyST), and can automatically fix many violations with the `--fix` flag. The tool is designed for speed and includes intelligent caching to skip unchanged files on subsequent runs.

When installed via pip, rumdl arrives as a pre-built binary with no runtime dependencies, making it a single-command install. It integrates with CI/CD pipelines, pre-commit hooks, and editor LSP servers. Configuration is TOML-based and discoverable, and it supports both text and JSON output formats for programmatic use.

Use it for:

- Enforce consistent Markdown style across a documentation repository or wiki in CI/CD pipelines.
- Auto-fix common Markdown formatting issues (spacing, heading levels, list markers) across many files at once.
- Integrate into a pre-commit hook to catch Markdown violations before they reach version control.
- Lint Markdown in multiple flavors (GFM, MDX, Quarto) within a single project without switching tools.
- Watch mode linting during documentation writing with editor integration via LSP.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

A Rust-based Markdown linter and formatter that checks files against 82 lint rules and can automatically fix violations, installable via pip as a pre-built binary with zero runtime dependencies.

Yes, if you maintain Markdown documentation and want a fast, zero-dependency linter with broad rule coverage and auto-fix capability. The active maintenance, recent release cycle, and permissive license make it low-risk. Install friction is medium due to platform-specific wheels, but that is typical for Rust-compiled tools and does not affect usability once installed.

## Install

pip install rumdl
uv add rumdl
poetry add rumdl

## Installing rumdl

Before you install: Medium install friction due to platform-specific wheels, but the package itself carries no runtime dependencies and is actively maintained with a recent release cycle (2 days since last release).

License in practice: MIT license is permissive; you can use, modify, and distribute this package freely with minimal restrictions.

Quickstart:

pip install rumdl
rumdl check .
rumdl check --fix .

Verify before relying:

- Whether the pip-installed version includes all 82 lint rules mentioned in the description or if some are Rust-only features.
- Performance characteristics on typical project sizes (the description benchmarks against 478 files but doesn't quantify typical speedup vs. alternatives).
- Whether configuration via pyproject.toml works identically to TOML-based config files.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: medium
- Maintenance: active
- Downloads: 832.2K/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

markdown linter, markdown formatter, lint markdown files, markdown style checker, markdown quality tool, fast markdown linting, markdown auto-fix, markdown-linting, rust-binary, ci-cd-friendly

[View on SkillFed](https://skillfed.io/packages/rumdl) · [View on PyPI](https://pypi.org/project/rumdl/)