rumdl — Markdown Linter

Real-time Markdown linting with auto-fix for GitHub and GitLab.

rumdl is a fast, privacy-first Markdown linter for your browser. All processing happens locally via WebAssembly — zero network requests, no data ever leaves your machine. Get instant feedback as you write issues, pull requests, comments, and wiki pages on GitHub and GitLab. Stop getting review comments about Markdown formatting. Features: • 60+ lint rules covering headings, lists, links, code blocks, and more • Line markers showing exactly which lines have problems • Warning panel with rule details, line numbers, and descriptions • One-click "Fix All" for auto-fixable problems • Disable or configure individual rules from the extension popup • Automatically matches your site's dark or light theme • Keyboard shortcuts for fast navigation Supported sites: • GitHub (issues, pull requests, comments, wikis, discussions) • GitLab (issues, merge requests, comments, wikis) Keyboard shortcuts: • Cmd/Ctrl+Shift+L — Toggle warning panel • Cmd/Ctrl+Shift+F — Fix all problems • Cmd/Ctrl+. — Fix problem at cursor • Cmd/Ctrl+Alt+] — Next warning • Cmd/Ctrl+Alt+[ — Previous warning Open source at github.com/rvben/rumdl-chrome-extension