pdf-ocr-cli

pdf-ocr-cli is a lightweight, zero-system-dependency CLI utility designed to bridge the gap between static scanned documents and searchable digital assets.

Unlike traditional OCR tools that require complex system-level installations of Tesseract and its language data, this tool leverages Tesseract.js (WebAssembly) to run the OCR engine directly within the Node.js runtime. It features a parallelized processing pipeline that scales across multiple CPU cores, making it efficient for large documents (100+ pages).

Key Features

• Searchable PDF Generation: Automatically merges OCR text layers back into a high-quality PDF.
• Parallel Execution: Configurable worker pools to maximize hardware utilization.
• Zero-Config OCR: No need for tesseract-ocr system binaries or manual language data management (WASM-based).
• Dual Output: Generates both a .txt transcription and a searchable _OCRed.pdf simultaneously.
• Developer Friendly: Built with Node.js, providing a clean CLI interface with real-time progress tracking.

Prerequisites

This tool requires the following system utilities to be present:

• poppler-utils (for pdftoppm)
• ghostscript (for gs)

Installation

npm install -g pdf-ocr-cli

Usage

pdf-ocr input.pdf

Options

• -o, --output <prefix>: Custom prefix for output files (defaults to input filename).
• -w, --workers <number>: Number of parallel workers (default: 4).
• -k, --keep: Keep temporary image files after completion.
• -h, --help: Show help.

License

This project is licensed under the ISC License - see the LICENSE file for details.