# Stirling PDF — Self-Hosted PDF Editor & Toolkit

> Stirling PDF is the #1 open-source PDF tool on GitHub. Merge, split, convert, compress, OCR, sign, and edit PDFs — all self-hosted with no data leaving your server.

## Install

Save the content below to `.claude/skills/` or append to your `CLAUDE.md`:

## Quick Use

```bash
docker run -d --name stirling-pdf -p 8080:8080 
  -v stirling-data:/usr/share/tessdata 
  frooodle/s-pdf:latest
```

Open `http://localhost:8080` — start editing PDFs immediately, no account needed.

## Intro

**Stirling PDF** is a self-hosted PDF manipulation tool that handles virtually every PDF operation you might need. With 76.5K+ GitHub stars, it's the most popular PDF application on GitHub, providing merge, split, convert, compress, OCR, sign, watermark, and dozens more operations — all through a clean web interface with zero data leaving your server.

## What Stirling PDF Does

50+ PDF operations organized by category:

**Page Operations**
- Merge multiple PDFs into one
- Split PDF by pages, size, or bookmarks
- Rotate, reorder, and remove pages
- Extract specific page ranges
- Add page numbers

**Conversion**
- PDF ↔ Image (PNG, JPEG, TIFF, WebP)
- PDF → Word (DOCX), Excel, PowerPoint
- HTML → PDF, Markdown → PDF
- PDF ↔ PDFA (archival format)

**Security**
- Add/remove password protection
- Add digital signatures
- Redact sensitive content
- Add watermarks (text or image)
- Set permissions (print, copy, edit)

**Document Processing**
- OCR (extract text from scanned PDFs)
- Compress PDF file size
- Flatten forms
- Extract images from PDF
- Add/edit metadata

**Advanced**
- Compare two PDFs visually
- Auto-rename based on content
- Multi-page layout (2-up, booklet)
- Repair corrupted PDFs

## Self-Hosting

### Docker (Simple)

```bash
docker run -d --name stirling-pdf 
  -p 8080:8080 
  -v ./training-data:/usr/share/tessdata 
  -v ./configs:/configs 
  -e DOCKER_ENABLE_SECURITY=false 
  frooodle/s-pdf:latest
```

### Docker Compose (with OCR languages)

```yaml
services:
  stirling-pdf:
    image: frooodle/s-pdf:latest
    ports:
      - "8080:8080"
    volumes:
      - ./training-data:/usr/share/tessdata
      - ./configs:/configs
      - ./logs:/logs
    environment:
      DOCKER_ENABLE_SECURITY: "false"
      INSTALL_BOOK_AND_ADVANCED_HTML_OPS: "true"
      LANGS: "zh_sim,zh_tra,eng,jpn,kor"  # OCR languages
    restart: unless-stopped
```

### Full Version (with LibreOffice)

```bash
# Full version includes Word/Excel/PPT conversion
docker run -d frooodle/s-pdf:latest-fat
```

## Key Features

### API Access

Every operation is available via REST API:

```bash
# Merge PDFs
curl -X POST http://localhost:8080/api/v1/general/merge-pdfs 
  -F "fileInput=@file1.pdf" 
  -F "fileInput=@file2.pdf" 
  -o merged.pdf

# Convert PDF to images
curl -X POST http://localhost:8080/api/v1/convert/pdf/img 
  -F "fileInput=@document.pdf" 
  -F "imageFormat=png" 
  -F "dpi=300" 
  -o images.zip

# OCR a scanned PDF
curl -X POST http://localhost:8080/api/v1/misc/ocr-pdf 
  -F "fileInput=@scanned.pdf" 
  -F "languages=chi_sim+eng" 
  -o ocr-result.pdf

# Compress PDF
curl -X POST http://localhost:8080/api/v1/general/optimize-pdf 
  -F "fileInput=@large.pdf" 
  -F "optimizeLevel=3" 
  -o compressed.pdf
```

### Multi-Language OCR

Stirling PDF uses Tesseract OCR with support for 100+ languages:

| Language | Code |
|----------|------|
| English | eng |
| Simplified Chinese | chi_sim |
| Traditional Chinese | chi_tra |
| Japanese | jpn |
| Korean | kor |
| German | deu |
| French | fra |
| Spanish | spa |

### Pipeline Operations

Chain multiple operations together:
```
Input PDF → OCR → Compress → Add Watermark → Password Protect → Output
```

## Why Self-Host PDF Tools?

```
Cloud PDF tools (iLovePDF, SmallPDF, etc.):
✗ Your documents uploaded to third-party servers
✗ File size limits on free tier
✗ Monthly subscription for full features
✗ Privacy concerns for sensitive documents

Stirling PDF:
✓ Documents never leave your server
✓ No file size limits
✓ All features free, forever
✓ Perfect for sensitive/legal/medical documents
```

## FAQ

**Q: Does Stirling PDF support Chinese OCR?**
A: Yes. Configure `chi_sim` (Simplified Chinese) or `chi_tra` (Traditional Chinese) via the LANGS environment variable. Language packs download automatically on first use.

**Q: What's the difference between the standard and "fat" images?**
A: The standard image includes basic PDF operations. The fat image additionally bundles LibreOffice, enabling PDF ↔ Word/Excel/PPT conversion. Fat image is about 1.5GB; standard is about 400MB.

**Q: Any file size limits?**
A: The self-hosted version has no file size limit. Processing speed depends on server resources. For large-file OCR, allocate at least 2GB RAM.

## Source & Thanks

- GitHub: [Stirling-Tools/Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF) — 76.5K+ ⭐
- Website: [stirlingpdf.io](https://stirlingpdf.io)

---
Source: https://tokrepo.com/en/workflows/stirling-pdf-self-hosted-pdf-editor-toolkit-fc325975
Author: Script Depot