MDMA
MDMA app icon

MDMA: Markdown Viewer

Markdown, beautifully rendered. Real math, diagrams and charts drawn right in the page, in a fast, native Mac app that updates the moment the file changes.

Coming soon to the Mac App Store.

Free to try for 14 days. Then MDMA Lifetime, a one-time purchase that includes every future update. For Mac with macOS 14.4 or later.

MDMA showing a reef survey with an outline, a callout and a line chart

Everything Markdown can hold

Open any .md file and read it the way it was meant to look, or write it with a live preview beside you.

Math like a textbook

KaTeX typesetting for inline, displayed, aligned and numbered equations, in every common syntax: $…$, $$…$$, \(…\), \[…\] and math blocks.

Diagrams and charts

Mermaid, Graphviz and mind maps; Vega-Lite, Chart.js and Plotly, including interactive 3D; function plots from one line, and CSV data as tables.

Write with a live preview

Editor, preview, or both side by side with scroll sync. Smart lists, formatting shortcuts, find and replace. Files stay plain Markdown.

Live reload for AI agents

When an editor, a script or an AI agent saves the file, MDMA re-renders at once and marks what changed. Follow Changes scrolls to each edit.

Five themes, light and dark

Modern, GitHub, Academic, Paper and Midnight. Charts, diagrams and fonts adapt to each theme and to dark mode.

Quick Look and export

Press Space in Finder to preview a Markdown file. Export to PDF or standalone HTML, or print.

A closer look

Lecture notes on Fourier analysis with displayed and numbered equations in the Academic theme
Real math typesetting. Numbered equations in the Academic theme.
A Mermaid flowchart and a 3D Plotly surface in the Midnight theme
Diagrams and charts in the page. Mermaid and a 3D Plotly surface in Midnight.
The Markdown source and its preview side by side in the Paper theme
Write with a live preview. Source and preview side by side, scrolled together.
A migration plan with the blocks that just changed marked in the margin
Updates as the file changes. Blocks an AI agent just wrote are marked in the margin.
The same document in the Modern, Academic, Paper, GitHub and Midnight themes
Five themes. Modern, Academic, Paper, GitHub and Midnight.

Private by design

MDMA collects no data. The details are in the Privacy Policy.

  • No accounts, no analytics, no ads and no tracking.
  • MDMA reads only the documents you open and the folders you allow, and saves only where you tell it to.
  • Math, diagrams, charts and fonts are rendered on your Mac with code inside the app; nothing is uploaded.
  • The trial and MDMA Lifetime are purchases through Apple; we never see your payment details.

Coming soon

MDMA will be on the Mac App Store, free to try for 14 days. Questions? Visit Support or write to .