Beautiful rendering, instant preview, table of contents, syntax highlighting, KaTeX math, Mermaid diagrams — and a built-in split-view editor. All in a native macOS app.
Requires macOS 14 Sonoma or later · Apple Silicon & Intel
The idea for MDViewer came from wanting a lightweight way to read .md files when working with Claude Code or Codex from the terminal.
Then we wanted to edit them too — so v1.1 adds a built-in split-view editor. Viewer on the right, editor on the left, live preview as you type.
Features
Designed for developers, writers, and anyone who works with Markdown files every day.
Opens and renders Markdown files instantly. Watches for file changes and live-reloads as you edit.
Auto-generated TOC sidebar from headings. Click to jump to any section with smooth scrolling.
Visual thumbnail strip lets you browse long documents at a glance and jump to any page.
40 languages highlighted with Shiki. Light and dark themes that follow macOS appearance.
Render inline and block LaTeX math beautifully with KaTeX — no extra setup required.
Flowcharts, sequence diagrams, Gantt charts, and more rendered directly in the document.
Local Markdown links open in the app. External links open in the browser. Images load from disk.
Print or export your document to PDF with a single click, preserving all styles and formatting.
Toggle a split-view editor with ⌘E. Edit on the left, live preview on the right. Save with ⌘S.
Distributed with Developer ID signing and Apple notarization for safe, Gatekeeper-friendly installation.
Runs in the macOS App Sandbox. Remote images stay blocked until you allow them — with an Ask / Always / Never privacy control.
Get started
No Homebrew, no setup, no configuration needed.
Open the .dmg and drag MDViewer.app to your Applications folder.
Double-click any Markdown file or drop it onto the MDViewer icon in the Dock.
Open Source
MDViewer is built on these open-source libraries. Full copyright notices and license texts are in THIRD_PARTY_NOTICES.md.
| Library | Purpose | License |
|---|---|---|
|
v18.0.6
|
Parses Markdown text and converts it to HTML for rendering. | MIT |
|
v4.3.1
|
Syntax highlighting for 40 programming languages using VS Code grammar. Supports dual light/dark themes via CSS variables. | MIT |
|
v0.17.0
|
Renders LaTeX math expressions — both inline $…$ and block $$…$$ — as high-quality HTML. |
MIT |
|
v11.16.0
|
Renders diagrams from text definitions — flowcharts, sequence diagrams, Gantt charts, and more. | MIT |
|
v3.4.12
|
Sanitizes the Markdown-derived HTML before display, stripping scripts and unsafe markup. | Apache-2.0 / MPL-2.0 |