TextEdit for Markdown files, with a CodeMirror 6 core
MarkEdit is a free, open-source Markdown editor for macOS that behaves like TextEdit but only handles Markdown. Documents stay as plain-text files on disk, and syncing them is left to iCloud, Git or whatever else you already use. The interface is AppKit and the settings are SwiftUI, while the editing surface is CodeMirror 6, rendered in the system WebView instead of shipping inside Electron. The universal DMG for version 1.37.0 is 4.7 MB; the Apple Silicon build is 3.4 MB.
Strict GFM, multiple carets and macOS services
- GitHub Flavored Markdown with nothing added: the editor puts no proprietary syntax on top of the spec.
- Multi-caret editing and code folding: Cmd-click adds a caret, and every Markdown command applies to all carets and selections at once.
- System features left in place: force-click word lookup, spell checking as you type, inline predictions, Apple Intelligence Writing Tools, Services, Shortcuts and AppleScript.
- Popover previews for tables, LaTeX formulas and Mermaid diagrams, without leaving the source text.
- Customization through plain files:
editor.cssandeditor.js, kept in the Documents folder of the app's container, restyle the editor and change its behavior. MarkEdit-api hands extensions the CodeMirrorEditorView. - Extension manager since 1.34.0: full HTML preview, themes, visual table editing and AI-assisted writing install from inside the app.
- Quick Search since 1.37.0: Shift-Cmd-O looks through recent and bookmarked files, the document's headings and text, and menu commands.
- A single network request, to the GitHub releases API, to check for updates. The project runs no server and collects no user data.
macOS 26 only, sandboxed, export left to Pandoc
Version 1.37.0 requires macOS Tahoe 26. The macos-15 release marks 1.36.0 as the last build for Sequoia, and the macos-12, macos-13 and macos-14 releases are still available for older systems. Writing Tools also need an Apple Silicon Mac.
There is no whole-document preview and no export, and the wiki defends both choices. Full HTML preview comes from the MarkEdit-preview extension. PDF or Word output goes through Pandoc: MarkEdit copies the command for you to paste into Terminal, and Pandoc options sit in a defaults file, pandoc.yaml, inside the app's container.
Code block highlighting is an extension. Since 1.34.0 the language-data package no longer ships with the app, so syntax highlighting inside fenced code blocks requires the Language Data extension.
The sandbox decides how files are reached. MarkEdit cannot make itself the default app for .md files; that is set by hand in Finder's Get Info window. Keeping access to a folder outside the container, for Quick Search for example, means adding it as a bookmark from the File menu. No command-line tool is bundled.
The README aims for balance across four criteria. Size, speed, native integration and correctness are traded against each other, and the project says it does not try to win any one of them. In its own comparison, Electron apps are much bigger, TextKit-based editors struggle with a 10 MB file, performance-first Rust editors lack native features, and editors that parse Markdown with regular expressions fail on correctness. The wiki adds that MarkEdit is not a note-taking app or a knowledge base.
Latest release: 1.37.0, on October 18, 2026. Six minor versions shipped between 1.32.0 on April 21 and 1.37.0, and the most recent commit landed on October 27. The wiki's Philosophy page calls the app "close to complete" with few features planned, and the README asks contributors to discuss any behavior change before opening a pull request.