| Platform | Download | Notes |
|---|---|---|
| macOS | WinDown3000-macOS.dmg | Drag to Applications |
| Windows | WinDown3000-SingleFile.exe | Single file, no install needed |
| Windows (zip) | WinDown3000-Windows-x64.zip | Extract and run |
| Windows (installer) | WinDown3000-Setup.exe | Start Menu + .md file association |
WinDown 3000 is a free, lightweight Markdown viewer and editor for macOS and Windows. Open any .md file and instantly see a beautifully rendered preview alongside the source. No bloat, no account required, no internet needed.
Built with C++ and Qt for native speed. Based on MacDown 3000, the popular macOS Markdown editor.
- View README files, documentation, notes, and any Markdown content with live-rendered preview
- Edit Markdown with syntax highlighting, auto-completion, and instant preview
- Export your documents to HTML or PDF
- Present technical docs with code highlighting, math notation, and diagrams
| WinDown 3000 | VS Code | Notepad++ | Online editors | |
|---|---|---|---|---|
| Single file, no install | Yes | No | No | N/A |
| Instant live preview | Yes | Extension needed | No | Some |
| Math/diagram support | Yes | Extension needed | No | Some |
| Works offline | Yes | Yes | Yes | No |
| Lightweight | ~30 MB | ~400 MB | ~5 MB | N/A |
| Free & open source | Yes | Yes | Yes | Varies |
Open a file and see it rendered in real time, side-by-side with the source. The split-pane view with synchronized scrolling makes it easy to read and edit at the same time.
- GitHub Flavored Markdown — tables, strikethrough, autolinks, task lists
- Fenced code blocks with language identifiers
- Footnotes, superscript, highlight, and underline extensions
- CommonMark compatible
Code blocks are highlighted in both the editor and preview using Prism, supporting 200+ programming languages.
- Math notation via MathJax —
$$E=mc^2$$,\[...\],\(...\) - Mermaid diagrams — flowcharts, sequence diagrams, Gantt charts
- Graphviz — dot language diagrams
- Jekyll front-matter detection
- 15 editor themes — Tomorrow, Solarized, Mou, Writer, and more
- 8 preview CSS themes — GitHub, Clearness, Solarized
- Auto-completion — bracket/quote pairing, smart list continuation
- Find and Replace — with regex, case-sensitive, and whole-word options
- Formatting toolbar — bold, italic, headings, lists, links, code
- Keyboard shortcuts — full set for efficient editing
- Word count — live word and character count
- Drag-and-drop — open files by dropping onto the window
- Export — HTML and PDF
Full preferences dialog with control over every aspect: font, theme, margins, Markdown extensions, preview rendering, code highlighting, and more.
- macOS 11.0 (Big Sur) or later
- Windows 10 or later (x64)
- No other dependencies
- CMake 3.21+
- Qt 6.5+ (with WebEngine module)
- C++17 compiler (MSVC 2019+)
git clone https://github.com/andrewhofmann/WinDown3000.git
cd WinDown3000
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release
ctest --test-dir build --build-config Release --output-on-failureWinDown 3000 is a ground-up C++/Qt port of MacDown 3000 (Objective-C/Cocoa):
| Component | Technology |
|---|---|
| Markdown parsing | Hoedown (C library) |
| Editor | QPlainTextEdit + QSyntaxHighlighter |
| Preview | WebView2 (Windows) / QWebEngineView (dev) |
| Code highlighting | Prism.js |
| Math rendering | MathJax |
| Diagrams | Mermaid + Graphviz |
| Settings | QSettings |
128 tests across 6 test suites run on every commit:
test_markdown_renderer — 35 tests (rendering, extensions, templates)
test_theme_parser — 9 tests (theme file parsing)
test_preferences — 35 tests (defaults, persistence, signals)
test_document — 16 tests (file I/O, state management)
test_editor — 20 tests (editing, auto-complete, formatting)
test_find_replace — 13 tests (search, replace, regex)
MIT License. See the LICENSE directory for details.
- MacDown 3000 by Schuyler Erle
- MacDown by Tzu-ping Chung
- Mou by Chen Luo
Contributions welcome! File an issue for bugs, features, or questions.