EPUB Chapter Merger

A Node.js CLI tool to intelligently merge short chapters in EPUB files while preserving reading flow.

Features

• 📖 Smart Merging - Merges chapters based on word count threshold
• 🔢 Preserves Order - Maintains chapter sequence and hierarchy
• 🎯 Configurable - Set minimum words per merged chapter
• 📋 Dry Run - Preview changes before applying
• ✨ Clean Output - Generates valid EPUB3 files

Installation

npm install

Usage

# Basic usage - merge chapters under 2000 words
node merge-chapters.js input.epub -o output.epub

# Set custom minimum word count
node merge-chapters.js input.epub -o output.epub --min-words 3000

# Preview changes without modifying
node merge-chapters.js input.epub --dry-run

# Show verbose output
node merge-chapters.js input.epub -o output.epub --verbose

Options

Option	Description	Default
-o, --output <file>	Output EPUB file path	Required
-m, --min-words <n>	Minimum words per merged chapter	2000
-d, --dry-run	Preview without creating file	false
-v, --verbose	Show detailed progress	false

How It Works

1. Parses the EPUB structure (OPF, NCX, NAV)
2. Calculates word count for each chapter
3. Groups consecutive short chapters
4. Merges content while updating navigation
5. Outputs a new valid EPUB file

License

MIT License