Free PDF Protect Tool

Add strong password protection to your PDFs — 100% private, no server upload, uses AES-256 encryption.

Protect PDF with Password

Upload your PDF, set a password. Pages are rendered via PDF.js and the output is encrypted with AES-256-CBC using the browser's Web Crypto API. Your file never leaves your device.

Drag & drop your PDF here, or click below

Protection Settings

🔐 How this works: Your PDF pages are rendered to images via PDF.js, reassembled into a clean PDF by pdf-lib, then the entire file is encrypted with AES-256-CBC (Web Crypto API, PBKDF2 key derivation, 100,000 iterations). To open the protected file later, use the companion PDF Unlock tool with the same password.

Why Protect Your PDFs with Passwords?

PDFs often contain sensitive information — contracts, financial reports, medical records, legal documents, business proposals, tax returns, and intellectual property. Leaving them unprotected risks unauthorized access, editing, or copying.

Our free PDF Protect Tool uses your browser's built-in Web Crypto API (AES-256-CBC with PBKDF2 key derivation) — the same standard used by banks and governments. No software installation, no server upload, complete privacy.

Common Use Cases

  • Secure client contracts, NDAs, and freelance agreements before sending
  • Protect financial statements, invoices, and tax documents
  • Safeguard legal documents, wills, and court filings
  • Protect ebooks, manuals, and copyrighted content

Benefits

  • Maximum Privacy — File and password never leave your device
  • AES-256 Encryption — Military-grade via the Web Crypto API
  • No Limits — Free, unlimited, no watermarks
  • Cross-Platform — Desktop, tablet, and mobile

Frequently Asked Questions

Is my PDF and password secure?

Yes — 100% local. AES-256-CBC encryption with PBKDF2 key derivation. Nothing is sent to any server.

How do I open the protected file later?

Use the companion PDF Unlock tool on this site. Enter the same password — the file will be decrypted and you can download the unlocked PDF.

Why does the file have a .pdfp extension?

The .pdfp extension indicates the file is a protected/encrypted PDF container. The PDF Unlock tool reads this format. The original PDF is preserved inside.

What if I forget the password?

There is no recovery. AES-256 is mathematically unbreakable without the key. Store your password in a password manager.

Does it work on mobile?

Yes — fully responsive. Works on iOS Safari and Android Chrome.