4 Ways to Detect PDF Encryption｜Free Security Check Tool

1. Two Encryption Types

2. Detection Methods

1. Basic Inspection

   • Windows: File Properties → Security tab

   • Mac: Preview app → Lock icon in title bar

2. Adobe Acrobat Pro
   File → Properties → Security → "Security Method" field

3. Online Detector (Recommended)

   ✅ Tool: PDFSail Security Scanner

   • Key Features:
     ✓ Identifies encryption type instantly
     ✓ Lists restricted actions (printing/copying/etc.)
     ✓ Zero-upload technology (local browser processing)

   Steps:

   1. Go to https://www.pdfsail.com/

   2. Upload file → Get automated report

   3. View details & solution options

4. Command Line (Advanced)

   bash

    

   复制

    

   下载

   pdfinfo yourfile.pdf | grep "Encrypted"  # Returns "yes" or "no"  

3. Solutions for Encrypted PDFs

• Forget open password?: Use brute-force tools (limited success)

• Remove permissions:

  ✅ Try PDFSail Unlock Tool
  Why safe:

  • Processes files locally via JavaScript

  • Retains original formatting after unlocking

4. Security Warnings

⚠️ Never upload confidential PDFs to untrusted websites
⚠️ Financial/legal documents require offline software

Pro Tip: When encountering "view-only" PDFs, scan with PDFSail first. 95% permission locks can be removed in 1 click.