PDF-DarkMod - Offline Desktop PDF Dark Mode Converter

A standalone desktop application that converts your PDF files into beautiful, eye-friendly dark mode themes. Built entirely with Python and Tkinter, ensuring 100% privacy with complete offline processing—no Node.js, Electron, or cloud uploads required.

Credit to the original author of the web-based PDF Dark Mode tool, Chizkiyahu.

Features

• Standalone Desktop App: Pure native feel, lightweight, and works fully offline.
• Privacy First: Your files never leave your device.
• Beautiful Dark Themes: Includes custom tailored themes like Classic Inversion, Claude Warm, ChatGPT Cool, Sepia Dark, Midnight Blue, and Forest Green.
• Interactive & Zoomable Preview: Instantly preview your PDF page in the selected theme. Zoom in (+), zoom out (−), or scale to fit (Fit) with responsive scaling and dual-axis scrolling (horizontal/vertical scrollbars) to view the entire document even when minimized or deeply zoomed.
• Customizable Quality: Choose between fast conversions or high-quality (up to 300 DPI) rendering using NumPy optimizations.
• Bookmarks Preserved: Keeps your original PDF's table of contents and bookmarks intact.
• Immersive Dark UI: Polished interface featuring centered sidebar headers and a dynamically centered window titlebar (Windows-compatible).

Requirements

• Python 3.10+
• pip install pymupdf
• pip install numpy (Optional, but highly recommended for 15-20x faster processing speed)

Running the App

1. Clone or download this repository.
2. Install the required dependencies: pip install -r requirements.txt (or just install pymupdf).
3. Run the application:

   python main.py

Building as an Executable (Optional)

If you want to create a single standalone .exe file without needing Python installed on the target machine:

pip install pyinstaller
pyinstaller --onefile --windowed --name "PDF-DarkMod" main.py

License

This project is licensed under the MIT License. See the LICENSE file for more details.