Consistent Markdown.
Wherever you write.

rumdl checks and formats Markdown with a native Rust engine. Use it in your terminal, bring it into your editor, and keep the same project rules in CI.

Explore rumdl.dev Use in VS Code

Open source · MIT license · Built with Rust

Example README.md

# Notes

##First steps

A useful note.

MD018 Missing space after heading markers

Add a space: ## First steps

See what rumdl finds. Try your Markdown in the browser.

An open-source project I maintain

I’m Ruben Jongejan, founder of AM8 B.V. I maintain rumdl and publish its VS Code extension as rvben.

The project brings Markdown diagnostics, automatic fixes and formatting to the CLI, language server and editor integrations. A shared configuration keeps your conventions consistent across local work and automation.

This is the project’s home on AM8. Visit rumdl.dev for the product website, documentation and browser playground, or read why I built rumdl.

Try it on your Markdown

With uv installed, run a check from your project directory without a permanent rumdl installation:

Check without changing files

uvx rumdl check .

The check reports issues without rewriting files. Follow the quick start to apply fixes and format your Markdown.

For package-manager commands, supported platforms and project settings, use the installation guide and configuration reference.

In your editor. In your pipeline.

VS Code

Diagnostics, quick fixes and formatting while you write.

Meet the VS Code extension

Other editors

Use the JetBrains plugin or connect an LSP-compatible editor.

JetBrains plugin · Editor setup

Automation

Run the same project checks in CI and pre-commit hooks.

CI integration · Pre-commit setup

Documentation, source & support

Full documentation at rumdl.devInstallation, commands, configuration and the rule reference
Core engine & CLI sourceDevelopment, releases and contributions
Report a core or CLI issueInclude your command, configuration and a small Markdown example