Clean. Light. Free.
A Markdown editor.

mMDd is a minimal Markdown editor for macOS and Windows. Newsprint paper warmth, vintage red accent, no clutter — just you and the words.

Apple Silicon by default · Unsigned during launch — see install note. Windows build coming soon.

Features

Everything you need.
Nothing you don't.

No live preview hacks. No WYSIWYG bugs. No bloat. Just a clean Markdown editor that respects your file and your focus.

Three view modes

Preview, Split, Editor-only — cycle through them with ⌘E. The icon in the tab bar tells you which mode you're in.

Tabs that stay out of the way

Scroll, drag to reorder, middle-click to close. Right-click for Reveal in Finder, Copy Path, Close Others. ⌃Tab to cycle.

Outline sidebar

Toggle with ⌘⇧O. Walks every heading in the document — click to jump. Built lazily, so it never slows you down.

Find. Replace. Repeat.

⌘F to find, ⌘⌥F to replace. Match count, next/prev. Undo works exactly as you'd expect.

Task lists you can check

Click a checkbox in the preview. mMDd toggles [ ][x] in your source and marks the tab dirty so you don't lose it.

Focus mode

⌘. hides every chrome element. Just paper. The status bar comes back when you move the mouse.

Image zoom, PDF export

Double-click an image for a full-screen overlay. ⌘⇧E exports a clean PDF that matches your current theme.

Auto-save & atomic writes

Opt into 30-second auto-save. Every save is atomic — a temp file plus a rename, so a power cut never corrupts your draft.

Front matter handled

YAML and TOML front matter is stripped before rendering. Relative .md links open as new tabs. Images resolve from the file's folder.

Themes

Nine themes.
One feels like home.

Four ship free with every install. Five more come as a thank-you for supporters. Newsprint is the default — warm paper and vintage red.

mMDd
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
mMDd dark
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Solarized
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Night Owl
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Forest
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Coder
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Matrix
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Newsprint dark
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Newsprint · Default
A Few Lines

A clean room and an empty page — that's all you need to begin.

Pour the coffee. Open the file.

"a quiet line."
const idea = "spark";
Typography

Fonts that travel with the app.

Every font ships inside mMDd, so Mac and Windows render the same letterforms. Two free, six are a thank-you for supporters. Each theme remembers its own.

  • iA Writer Quattro

    Default

  • New York

  • Merriweather

  • Noto Serif

  • Inter

  • JetBrains Mono

  • Nanum Gothic Coding

  • VT323

    Pairs with Matrix

Support

mMDd is free.
Forever.

No subscription. No tracking. No upsell pop-ups. If mMDd makes your writing day a little nicer and you'd like to say thanks, supporters get a code that unlocks five extra themes and six extra fonts — a small token of gratitude, not a paywall.

Got a thank-you code?

  1. Open mMDd, click the gear icon next to the +.
  2. Scroll to Unlock and paste your code.
  3. Five Supporter themes and six Supporter fonts appear instantly. That's it.
First-time install · 30 seconds

Two clicks, one command,
and you're writing.

mMDd is unsigned during the free launch season, so macOS Gatekeeper will block the first launch. Three steps to get through it.

  1. Open the DMG. Drag mMDd.app onto the Applications shortcut.

  2. Open Terminal (Spotlight → type "Terminal"). Paste this line and hit Return:

    xattr -dr com.apple.quarantine /Applications/mMDd.app
  3. Double-click mMDd in Applications. Done — it opens, you're in.

The command above tells macOS "I trust this file" — it removes the quarantine flag Safari attached during download. It changes only mMDd; nothing else on your Mac. The friction disappears entirely once mMDd is signed & notarized.

Want every .md file to open in mMDd? Right-click any Markdown file → Get Info → under "Open with" pick mMDd → click "Change All…". The "Open With" submenu sets a one-off choice; this is the only place macOS records a real default.

Intel Mac? Download the Intel build instead. (The big button above is Apple Silicon.)