ReadIt — Free, Fast & Native PDF Reader 📚

A modern, lightning-fast, and 100% free PDF reader desktop application built entirely with Python. Designed to be completely offline with no subscriptions, no ads, and no paywalls. It leverages PyQt6 for a native, premium look and feel and PyMuPDF for high-performance rendering.

🌟 Key Features

• 🚀 Lightning-Fast Rendering: Powered by PyMuPDF (fitz) with lazy page loading for smooth, lag-free scrolling, even on massive documents.
• 🎨 Modern, Premium UI: Clean, intuitive interface featuring fully integrated Dark Mode and Light Mode.
• 🔍 Powerful Search: Fast in-document text search with visual hit highlighting and easy navigation between matches.
• 📑 Sidebar Navigation: Quickly browse through documents using the built-in, lazy-loaded thumbnail sidebar view.
• 👁️ Flexible Viewing Options: Adaptive zoom controls including Fit Width, Fit Page, mouse-wheel zooming, and custom zoom percentages.
• 🔒 100% Offline & Private: No cloud uploads, no telemetry. Your files stay perfectly secure on your local machine.
• 🖱️ Drag & Drop Support: Simply drag and drop any PDF file onto the application window to open it instantly.

📸 In Action

🛠️ Prerequisites

Before you begin, ensure you have the following installed:

• Python 3.8+
• PyQt6 (>=6.6)
• PyMuPDF (>=1.24)

📥 Installation

1. Enter the project directory:

   cd "path/to/project/folder"

2. Install the required dependencies via pip:

   pip install -r requirements.txt

🚀 Usage

Run the application directly from the terminal:

python main.py

You can also bypass the welcome screen and directly open a PDF file by passing it as a command-line argument:

python main.py "path/to/document.pdf"

⌨️ Keyboard Shortcuts

Navigate like a pro with these handy shortcuts:

Shortcut	Action
Ctrl + O	Open PDF
Ctrl + F	Open Search / Find
Ctrl + P	Print Document
Ctrl + + / Ctrl + -	Zoom In / Zoom Out
Ctrl + Mouse Wheel	Zoom In / Zoom Out
T	Toggle Sidebar
F11	Toggle Fullscreen
Left Arrow / Right Arrow	Previous / Next Page

📁 Project Structure

• main.py: Application entry point, main window logic, toolbars, and welcome screen.
• pdf_viewer.py: The core rendering engine handling PyMuPDF integration, scaling, lazy rendering, and search highlights.
• sidebar.py: Navigation sidebar containing lazy-loaded page thumbnails.
• search_bar.py: UI and logic for the in-document search functionality.
• theme.py: Custom QSS (Qt Style Sheets) defining the Dark and Light modes.

📦 Deployment (Windows .exe)

To build the application into a standalone, double-clickable Windows .exe file (so users don't need Python installed):

1. Install PyInstaller (Note: v5.13.2 is highly recommended to avoid hook-resolution issues with PyMuPDF on newer Python versions):

   pip install pyinstaller==5.13.2

2. Run the build command, explicitly giving PyInstaller the path to the PyMuPDF (fitz) binaries:

   pyinstaller --name "ReadIt" --windowed --onefile --clean --add-data "C:/path/to/your/python/Lib/site-packages/fitz;fitz" main.py

   (Ensure you replace the Python path with your actual local environment python path).
3. Once the build finishes, look inside the generated dist folder. You will find your standalone ReadIt.exe inside!

---

Built with ❤️ in Python