PDF API - How to Merge, Split & Compress PDFs with a REST API

Learn how to programmatically merge, split, and compress PDFs using a REST API. Python, JavaScript, and cURL code examples included.

Why Automate PDF Processing?

PDFs are the universal document format, but manipulating them programmatically is surprisingly complex. Libraries like PyPDF2, pdf-lib, or Apache PDFBox require significant setup and have inconsistent APIs. A PDF REST API handles the heavy lifting — send files in, get processed files back.

Common automation scenarios:

• Invoice systems — merge monthly invoices into a single PDF for accounting
• Report generation — split large reports into per-department sections
• Email attachments — compress PDFs before sending to reduce size by 40-60%
• Document management — add watermarks, page numbers, or password protection
• Data extraction — pull text from scanned contracts or receipts

PDF Toolkit API Features

Our PDF API supports 11 operations, all accessible via simple REST endpoints:

Merge Multiple PDFs

Combine two or more PDF files into a single document. The order of files in the request determines the page order in the output.

cURL

curl -X POST "https://api.commandsector.in/api/pdf/merge?api_key=YOUR_KEY" \
  -F "files=@invoice1.pdf" \
  -F "files=@invoice2.pdf" \
  -F "files=@invoice3.pdf" \
  --output merged.pdf

Python

import requests

files = [
    ("files", open("invoice1.pdf", "rb")),
    ("files", open("invoice2.pdf", "rb")),
    ("files", open("invoice3.pdf", "rb")),
]
response = requests.post(
    "https://api.commandsector.in/api/pdf/merge",
    params={"api_key": "YOUR_KEY"},
    files=files
)
with open("merged.pdf", "wb") as f:
    f.write(response.content)

Split PDFs

Extract specific pages from a PDF. Specify page ranges like "1-3,5,7-10" to create a new PDF with only those pages.

# Extract pages 1-3 and 5
curl -X POST "https://api.commandsector.in/api/pdf/split?api_key=YOUR_KEY" \
  -F "file=@document.pdf" \
  -F "pages=1-3,5" \
  --output extract.pdf

Compress PDFs

Reduce PDF file size by optimizing images and removing unnecessary data. Typical compression: 40-60% size reduction without noticeable quality loss.

curl -X POST "https://api.commandsector.in/api/pdf/compress?api_key=YOUR_KEY" \
  -F "file=@large-report.pdf" \
  --output compressed.pdf

# Check the size difference
ls -lh large-report.pdf compressed.pdf

More Operations

Add Watermark

curl -X POST "https://api.commandsector.in/api/pdf/watermark?api_key=YOUR_KEY" \
  -F "file=@contract.pdf" \
  -F "text=CONFIDENTIAL" \
  -F "opacity=0.3" \
  --output watermarked.pdf

Extract Text

curl -X POST "https://api.commandsector.in/api/pdf/extract-text?api_key=YOUR_KEY" \
  -F "file=@document.pdf"
# Returns: {"text": "Full text content of the PDF...", "pages": 5}

Password Protect

curl -X POST "https://api.commandsector.in/api/pdf/protect?api_key=YOUR_KEY" \
  -F "file=@sensitive.pdf" \
  -F "password=my-secure-pass" \
  --output protected.pdf

Quick Start

Get your free API key and start making requests in minutes.

curl "http://147.224.212.116/api/..." \
  -H "X-API-Key: YOUR_API_KEY"