debooklet

A TypeScript CLI tool that reverses pdfbooklet - converting booklet-formatted PDFs back to normal sequential page order.

Overview

When you create a booklet for printing, pages are rearranged in a specific order so that when the sheets are folded and stacked, the pages appear in the correct sequence. This tool reverses that process, extracting the original pages from a booklet PDF.

What is a Booklet?

A booklet PDF is designed for duplex printing where:

• Each A3 (or larger) sheet contains two A4 (or smaller) pages side-by-side
• Pages are arranged for folding in half
• When folded and stacked, pages read sequentially

Example booklet layout for 16 pages (8 sheets):

Sheet 0: [LEFT: 16] [RIGHT: 1]   ← Outermost sheet
Sheet 1: [LEFT: 2]  [RIGHT: 15]
Sheet 2: [LEFT: 14] [RIGHT: 3]
Sheet 3: [LEFT: 4]  [RIGHT: 13]
Sheet 4: [LEFT: 12] [RIGHT: 5]
Sheet 5: [LEFT: 6]  [RIGHT: 11]
Sheet 6: [LEFT: 10] [RIGHT: 7]
Sheet 7: [LEFT: 8]  [RIGHT: 9]   ← Innermost sheet

When folded and nested, these sheets create a booklet with pages 1-16 in order.

Installation

Option 1: Standalone Executable (Recommended - No dependencies!)

Download the pre-built executable for your platform from GitHub Releases:

Linux (x64):

wget https://github.com/YOUR_USERNAME/debooklet/releases/latest/download/debooklet-linux-x64
chmod +x debooklet-linux-x64
sudo mv debooklet-linux-x64 /usr/local/bin/debooklet

macOS (Intel):

wget https://github.com/YOUR_USERNAME/debooklet/releases/latest/download/debooklet-macos-x64
chmod +x debooklet-macos-x64
sudo mv debooklet-macos-x64 /usr/local/bin/debooklet

macOS (Apple Silicon):

wget https://github.com/YOUR_USERNAME/debooklet/releases/latest/download/debooklet-macos-arm64
chmod +x debooklet-macos-arm64
sudo mv debooklet-macos-arm64 /usr/local/bin/debooklet

Windows:

1. Download debooklet-win-x64.exe from the releases page
2. Rename to debooklet.exe (optional)
3. Add to your PATH or run directly

Option 2: npm/npx (Requires Node.js)

No installation - use npx:

npx debooklet input.pdf output.pdf

Global installation via npm:

npm install -g debooklet
debooklet input.pdf output.pdf

Option 3: From Source (Development)

git clone https://github.com/YOUR_USERNAME/debooklet.git
cd debooklet
npm install
npm run build
npm link  # Makes 'debooklet' available globally

Usage

# Basic usage
debooklet <input.pdf> <output.pdf>

# Show help
debooklet --help

# Show version
debooklet --version

Examples

# Convert a booklet back to normal page order
debooklet my-booklet.pdf output.pdf

# The tool shows progress as it extracts pages:
# Reading booklet PDF from: my-booklet.pdf
# Booklet has 8 sheets (16 logical pages)
# Extracting page 1: sheet 0, right side
# Extracting page 2: sheet 1, left side
# Extracting page 3: sheet 2, right side
# ...
# Saving debooklet PDF to: output.pdf
# ✓ Done!

How It Works

1. Loads the booklet PDF - Reads the input file containing A3 (or larger) sheets
2. Detects page count - Automatically determines total sheets and logical pages
3. Applies reverse booklet algorithm - Calculates which sheet and which side each page came from
4. Splits pages - Crops each A3 sheet to extract left and right A4 pages
5. Reorders sequentially - Assembles pages in normal reading order (1, 2, 3, 4...)
6. Saves output - Writes the debooklet PDF with pages in sequential order

The tool uses the standard booklet pattern where:

• Odd pages (1, 3, 5, 7, ...) appear on the RIGHT side of sheets
• Even pages (2, 4, 6, 8, ...) appear on the LEFT side of sheets
• Pages are distributed across sheets in a specific interleaved pattern for proper folding

Use Cases

• Digital distribution: Convert printed booklet PDFs to normal reading order for screen viewing
• Editing: Extract pages from booklet layouts for individual editing
• Archiving: Store documents in sequential order rather than booklet format
• Republishing: Convert booklet-formatted documents back to standard format

Technical Details

• Built with TypeScript for type safety
• Uses pdf-lib for PDF manipulation
• Uses yargs for CLI argument parsing
• Automatically handles crop boxes to split A3 sheets
• Preserves PDF quality and formatting
• Works with any booklet size (automatically detected)

Requirements

• Standalone executables: None! Just download and run
• npm/npx method: Node.js 14 or higher
• From source: Node.js 14+ and npm

Building Executables Locally

If you want to build the standalone executables yourself:

# Install dependencies
npm install

# Build for all platforms
npm run build:exe:all

# Or build for specific platforms
npm run build:exe:linux   # Linux x64
npm run build:exe:mac     # macOS (Intel & Apple Silicon)
npm run build:exe:win     # Windows x64

# Executables will be in the ./build directory

Publishing to npm

To publish this package to npm (requires npm account):

# Update version in package.json
npm version patch  # or minor, or major

# Build the project
npm run build

# Publish to npm
npm publish

Creating a Release

1. Update the version: npm version <patch|minor|major>
2. Push the tag: git push && git push --tags
3. GitHub Actions will automatically:
   • Run tests
   • Build executables for Linux, macOS, and Windows
   • Create a GitHub Release with all binaries

License

MIT