This is MacMD. I created it as a free, open-source Markdown editor for Mac.
Download the latest release (macOS 14 or later)
Here are some things you can do with MacMD.
- Essential formatting
- Live preview toggle
- Mermaid diagrams
- Agentic AI tool templates
- Customizable themes
The essential word processor features are here, too. Nothing fancy.
- Font, font size
- Bold [
Cmd-B], italics [Cmd-I],strikethrough[Cmd-Shift-X] Inline codeand fenced code blocks- Hyperlinks [
Cmd-K] - Checkboxes [
Cmd-Shift-L]- projects
- task lists
- groceries idk
- Word count, read-time estimate, numbered lines. These and more can be toggled on/off in the
Viewmenu. - Spelling and grammar check can be toggled in
Edit → Spelling and Grammar. - Word count, spelling check, and toolbar settings can also be found in
MacMD → Settings → Editing.
Mouse over the top of the doc and a toolbar will appear. On the far right side, there are three view options. From left to right:
- Edit View (Default): The default is this view, the standard single-pane view where you edit the doc.
- Split View: Split View lets you see a live preview of the formatting as you type, with the Edit Pane on the left and the Preview Pane on the right.
- Preview View: The last view lets you see the file in its formatted form. This is a good way to review before sharing or saving. The Preview Pane is view-only (except checkboxes, which you can tick right there), so just switch to one of the other views to make changes.
"This formatting is excessive!": If you prefer the no-frills experience, you can remove all formatting by switching to the Classic View: turn off View → Show Formatting [Cmd-/]. Formatting and theme remain viewable in the Preview Pane. Remember, the Preview Pane can be hidden by changing back to the default single-pane Edit View.
Fenced Mermaid code blocks render as real diagrams in the preview and in exports. Twelve diagram types are possible:
- flowchart
- sequence
- class
- state
- entity relationship
- Gantt
- pie
- mindmap
- git graph
- journey
- timeline
- quadrant
See mermaid-diagrams-example.md for examples of each.
Built-in templates for your AI/agentic tools, including SKILL.md, agent-name.md, CLAUDE.md, and AGENTS.md, can be found in File → New from Template.
These are ready for you or your AI of choice to edit and build from. SKILL.md and agent-name.md come with the YAML front matter Claude Code reads to decide when to use them.
Customize MacMD to your liking with pre-built and customizable themes that go beyond light and dark mode. Customization lives in MacMD → Settings → Appearance or [Cmd-,].
- Change the colors of your headings with a selection of pre-built themes (personally created by me).
- Create your personalized experience by choosing colors you prefer. Compatible with the dynamic light/dark mode automatic settings.
- Customize the background and cursor for a fully unique setup.
Is this level of customization necessary? Yes. If you said "no," you can choose from the basic themes, keep the default, or toggle to the Classic View.
Export to HTML and PDF
File → Export to HTML [Cmd-Shift-E]: Export the formatted preview as an HTML file, including all embedded diagrams and other elements.
File → Export to PDF: Export the formatted preview as a PDF.
File → Save [Cmd-S]: Save your .md file as plain Markdown. The preview is rebuilt from that text, so there is nothing extra to save. Want a copy? Hold [Option] with the File menu open and Duplicate becomes Save As.
MacMD is fully offline. It makes no network connections: no update checks, no crash reporting, no analytics. The preview and export render fully offline from a bundled engine, inside a web view with a strict content security policy, all network access denied, and no script execution from document content. The binary is code-signed with the hardened runtime enabled.
Security Reports: See SECURITY.md.
Grab the DMG from the latest release and drag MacMD to Applications. It is signed but not notarized, so approve it once on first launch: on macOS 15 or later, go to System Settings → Privacy & Security and click Open Anyway; on macOS 14, right-click the app and choose Open.
MacMD opens .md, .markdown, .mdown, and .mkd. To uninstall, drag it to the Trash. It leaves behind only its preferences file and small WebKit and cache folders under ~/Library.
Requires Xcode 16 or later. Open MacMD.xcodeproj and hit [Cmd-R], or:
xcodebuild -project MacMD.xcodeproj -scheme MacMD -configuration Release -destination 'platform=macOS' buildRun the tests the same way with xcodebuild test. Project layout and house rules are in CONTRIBUTING.md.
The repo ships a ready-to-use skill at skills/macmd/SKILL.md: the app's capability map, every defaults configuration key, and the full menu map, so an agent can open, configure, and verify MacMD on its own. Copy the macmd folder into ~/.claude/skills/ (or your agent's skill directory).
MIT. See LICENSE. Built by sleetcrash.