PDF Merger

A lightweight web application to add a cover or back page to one or multiple PDFs and download the results packaged as a ZIP file.

Features

• 📁 Drag-and-drop or click to select multiple main PDFs
• 📄 Drag-and-drop or click to select a single PDF to use as a cover or back page
• 🔀 Choose insertion position: First Page or Last Page
• 📦 Batch processing: Generate a ZIP file with all processed PDFs ready to download
• ⚡ Client-side processing: All work happens in your browser—no uploads to external servers

How It Works

1. Select or drag one or multiple PDFs into the "Main PDFs" section
2. Select or drag a PDF into the "PDF to Insert" section (this will be your cover/back page)
3. Choose the insertion position: "First Page" or "Last Page"
4. Click "Merge PDFs" and download the ZIP file with your processed PDFs

Live Demo & Screenshots

This is a simple web interface contained in a single index.html file with styling in style.css and logic in script.js. Open index.html in a modern browser to get started.

Dependencies

The application uses two libraries loaded via CDN:

• pdf-lib — JavaScript library for manipulating PDFs in the browser
• JSZip — JavaScript library for creating and reading ZIP files

Both are included automatically in index.html.

Installation & Local Setup

This is a static project with no build step required. To serve it locally and avoid browser file access restrictions, use a simple HTTP server:

Using Python 3

python3 -m http.server 8000
# Then open http://localhost:8000 in your browser

Using Node.js

npx http-server

Using PHP

php -S localhost:8000

Usage Tips

• File size: Works best with reasonably sized PDFs. Processing happens in the browser, so performance depends on available memory.
• Batch processing: For very large or many files, consider processing them in smaller batches.
• Browser compatibility: Works in modern browsers that support ES6 and the File API.

Limitations & Notes

• Client-side only: All processing happens in your browser. No data is sent to external servers.
• Performance: Maximum file size and performance depend on your browser and available system memory.
• PDF validation: The app assumes uploaded files are valid PDFs. Invalid files may produce unexpected results.
• Single cover/back page: Currently, each batch can only use one PDF as the cover/back page across all main PDFs.

Contributing

We welcome contributions! If you'd like to improve PDF Merger:

1. Fork this repository
2. Create a feature branch: git checkout -b feature/your-feature-name
3. Make your changes and test them locally
4. Commit with a clear message: git commit -m "Add feature description"
5. Push to your fork: git push origin feature/your-feature-name
6. Open a Pull Request and describe your changes

Ideas for Contributions

• Add support for inserting a page at any position (not just first/last)
• Implement compression options for the generated ZIP
• Add support for batch processing with different covers per file
• Improve error handling and user feedback
• Add keyboard shortcuts or other UX improvements
• Write unit tests
• Add multi-language support

License

This project is open source and available under the MIT License. Feel free to use it in your projects!

Support & Feedback

If you encounter any issues or have suggestions:

• 🐛 Report a bug: Open an issue and describe what went wrong
• 💡 Suggest a feature: Open an issue with your idea and why it would be useful
• 💬 Ask a question: Check existing issues first, then open a new one

About

Created with ❤️ for anyone who needs to batch-process PDFs in the browser.

---

Happy merging! 🚀