MarkSnap

A fast, lightweight Markdown viewer for Windows with theme support and a modern interface.

Features

• Instant Preview - View Markdown files with beautiful, GitHub-style rendering
• Tabbed Interface - Open multiple documents in tabs within a single window
• Single Instance - Double-clicking .md files opens them in the existing window as new tabs
• Light & Dark Themes - Choose between Light, Dark, or Follow System theme
• Custom Title Bar - Modern styled window with integrated controls
• Drag & Drop - Simply drag .md files onto the window to view them (supports multiple files)
• File Association - Register as the default handler for .md and .markdown files
• Live Refresh - Quickly reload the current file to see changes
• Session Restore - Remembers open tabs, window size, position, and theme between sessions
• Keyboard Shortcuts - Full keyboard navigation support
• Rich Markdown Support - Tables, task lists, code blocks, emojis, and more

Screenshots

MarkSnap displaying a Markdown file with syntax highlighting and dark theme

Installation

Prerequisites

• Windows 10/11
• .NET 8.0 Runtime or later
• WebView2 Runtime (included with modern Windows)

Download

Download the latest release from the Releases page.

Build from Source

git clone https://github.com/jasona/marksnap.git
cd marksnap
dotnet build -c Release

The executable will be in MarkSnap/bin/Release/net10.0-windows/.

Usage

Opening Files

There are several ways to open Markdown files:

1. Drag and Drop - Drag any .md or .markdown file onto the MarkSnap window
2. Open Button - Click the "Open" button in the toolbar to browse for a file
3. Command Line - Run MarkSnap.exe "path/to/file.md"
4. File Association - Double-click any .md file (after registering MarkSnap as the default handler)

Setting as Default Markdown Viewer

1. Open MarkSnap
2. Click "Set as Default" in the toolbar
3. Confirm the registration

Now double-clicking any .md file will open it in MarkSnap.

Changing Theme

1. Click "Settings" in the toolbar
2. Choose your preferred theme:
   • Follow system setting - Automatically matches Windows light/dark mode
   • Light - Light background with dark text
   • Dark - Dark background with light text
3. Click "Save"

Your theme preference is saved and restored on next launch.

Keyboard Shortcuts

Shortcut	Action
Ctrl+O	Open file
Ctrl+W	Close current tab
Ctrl+Tab	Next tab
Ctrl+Shift+Tab	Previous tab
F5 or Ctrl+R	Refresh current file

Markdown Support

MarkSnap uses Markdig for Markdown parsing, supporting:

• CommonMark - Full CommonMark specification
• Tables - GitHub Flavored Markdown tables
• Task Lists - Interactive checkboxes
• Code Blocks - Syntax highlighting for code
• Emojis - :emoji: shortcodes
• Strikethrough - deleted text
• Autolinks - Automatic URL detection
• And more - Advanced extensions enabled

Configuration

MarkSnap stores its settings in:

%LocalAppData%\MarkSnap\settings.json

Saved settings:

• Window position (X, Y)
• Window size (Width, Height)
• Maximized state
• Theme preference (Light, Dark, or System)
• Open file paths (for session restore)
• Active tab index

Tech Stack

• Framework: WPF (.NET 8/9/10)
• Markdown Engine: Markdig
• Rendering: WebView2 (Chromium-based)
• Language: C# 12

Project Structure

marksnap/
├── MarkSnap/
│   ├── App.xaml               # Application entry point and theme resources
│   ├── App.xaml.cs            # Application startup and single-instance logic
│   ├── MainWindow.xaml        # Main window UI with tabs and custom title bar
│   ├── MainWindow.xaml.cs     # Window logic, tab management, and rendering
│   ├── SingleInstanceManager.cs # Mutex and named pipe IPC for single instance
│   ├── SettingsWindow.xaml    # Settings dialog UI
│   ├── SettingsWindow.xaml.cs # Settings dialog logic
│   └── MarkSnap.csproj        # Project configuration
└── README.md

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Markdig - Fast, powerful Markdown processor for .NET
• WebView2 - Modern web rendering engine