MarkEdit is a free and open-source Markdown editor for macOS that combines the simplicity of TextEdit with dedicated Markdown support.
MarkEdit addresses the tension between editor bloat and performance by building a lightweight application that handles large files efficiently. The tool uses CodeMirror 6 for complex editing features like multi-caret editing and code folding, ensuring correctness through strict adherence to the GitHub Flavored Markdown specification rather than proprietary syntax. The native macOS interface preserves familiar behaviors including force-touch word lookup, inline predictions, and Writing Tools, while the 4 MB installer size keeps the application lean compared to Electron-based alternatives.
MarkEdit suits developers and writers who work on macOS and want a focused Markdown editor without unnecessary features or data collection. It performs well on large files, handling 10 MB documents with ease, which distinguishes it from TextKit-based editors that struggle at scale. The tool is extensible through CSS, JavaScript, and CodeMirror extensions, with official extensions providing preview panes, custom theming, and AI writing assistance. Those prioritizing native macOS integration and privacy will find this approach more aligned with their needs than performance-first editors built with other technologies that sacrifice native features.
The project maintains active development with regular updates distributed through both GitHub releases and Homebrew. The maintainers engage with the community through a Mastodon account and provide comprehensive documentation including philosophy and design rationale pages. The codebase is written in Swift and TypeScript, reflecting the native macOS implementation paired with web-based editor components.
