PDF Combiner

A fast, lightweight desktop application for combining multiple PDF files into one or splitting them apart. Built with Tauri (Rust) and Svelte.

Features

• Select multiple PDF files via native file picker
• Drag-and-drop reordering of files
• View page count for each PDF
• Combine into a single PDF with one click
• Dark theme UI
• Small binary size (~10-20MB)

Quick Start

Prerequisites

• Node.js (v18+)
• Rust (via rustup)
• Tauri CLI: cargo install tauri-cli

Linux/WSL additional dependencies:

sudo apt-get install -y libwebkit2gtk-4.1-dev build-essential curl wget file libxdo-dev libssl-dev libayatana-appindicator3-dev librsvg2-dev

Development

# Install dependencies
npm install

# Run in development mode (hot reload)
npm run tauri dev

First run will compile the Rust backend which takes a few minutes. Subsequent runs are fast.

Build for Production

npm run tauri build

Output binary location: src-tauri/target/release/bundle/

• Linux: .deb and .AppImage in bundle/deb/ and bundle/appimage/
• Windows: .msi and .exe in bundle/msi/ and bundle/nsis/
• macOS: .dmg and .app in bundle/dmg/ and bundle/macos/

Project Structure

pdf-combiner/
├── src/                      # Frontend (Svelte)
│   ├── routes/
│   │   └── +page.svelte      # Main UI component
│   └── app.css               # Tailwind CSS
├── src-tauri/                # Backend (Rust)
│   ├── src/
│   │   └── lib.rs            # PDF combining logic
│   ├── Cargo.toml            # Rust dependencies
│   └── tauri.conf.json       # Tauri configuration
├── package.json
└── vite.config.js

Tech Stack

Layer	Technology
Frontend	Svelte 5, TypeScript, Tailwind CSS
Backend	Rust, lopdf
Framework	Tauri 2
Build	Vite, Cargo

How It Works

1. File Selection: Uses Tauri's native dialog plugin for OS file pickers
2. PDF Parsing: Rust backend uses lopdf to read PDF structure and page counts
3. Combining: Objects from each PDF are remapped to new IDs and merged into a single document
4. Output: Combined PDF is compressed and saved to user-selected location

Commands

Command	Description
npm run tauri dev	Start development server with hot reload
npm run tauri build	Build production binary
npm run build	Build frontend only
npm run dev	Run frontend dev server only (no Tauri)

Configuration

Window Settings

Edit src-tauri/tauri.conf.json:

{
  "app": {
    "windows": [{
      "title": "PDF Combiner",
      "width": 700,
      "height": 600,
      "minWidth": 500,
      "minHeight": 400
    }]
  }
}

App Metadata

Edit src-tauri/Cargo.toml for Rust package info and src-tauri/tauri.conf.json for app identity.

WSL Notes

If running on WSL, you need a display server:

• Windows 11: WSLg is built-in, should work automatically
• Windows 10: Install VcXsrv or similar X server

Recommended IDE Setup

VS Code with extensions:

• Svelte
• Tauri
• rust-analyzer
• Tailwind CSS IntelliSense

License

MIT