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How to Password Protect a PDF — Free Encryption Tool | PDF AI Work Blog

PDF AI Work Team·July 30, 2026

Add password protection to any PDF with 256-bit AES encryption. The Protect PDF tool lets you set both user and owner passwords to control who can open and modify your document.

Two Types of Password Protection

  • User password (open password): Required just to view the document
  • Owner password (permissions): Controls printing, copying, editing — even if the document is open
  1. Open Protect PDF
  2. Upload your PDF
  3. Set a strong user password and/or owner password
  4. Choose permission restrictions
  5. Download the encrypted PDF

Use with a strong password — try our Password Generator. To remove protection: Unlock PDF. For permanent content removal: Redact PDF.

Free, no signup. Password protect your PDF now.

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