Encrypt PDF

Protect your PDF with 256-bit AES encryption. Add password protection and set usage restrictions.

Click to select PDF or drag and drop

Your files never leave your device.

What is PDF Encryption?

PDF encryption is a security method that protects your PDF documents by adding password protection and access restrictions. Using 256-bit AES encryption - the same standard used by banks and governments - your files become inaccessible without the correct password.

Why encrypt your PDFs?

  • Confidential Documents: Protect sensitive contracts, financial reports, or personal information
  • Legal Compliance: Meet data protection requirements (GDPR, HIPAA, etc.)
  • Content Control: Restrict printing, copying, or editing of your documents
  • Secure Sharing: Safely share files via email or cloud storage
  • Intellectual Property: Protect research, manuscripts, or proprietary information
  • Client Privacy: Secure client documents and communications

Security Features

  • ✓ 256-bit AES encryption
  • ✓ Separate user/owner passwords
  • ✓ Custom permissions
  • ✓ No file size limits
  • ✓ 100% browser-based
  • ✓ No data uploaded

How to Encrypt a PDF

1

Upload PDF

Select your PDF document. All processing happens locally in your browser - your files never leave your device or get uploaded to any server.

2

Set Passwords

Set user password (required to open) and optional owner password (for permissions). Choose strong passwords for maximum security.

3

Download Protected PDF

Download your encrypted PDF file. The document is now secured with 256-bit AES encryption and requires password to open.

Password Best Practices

Strong Passwords

  • Use 12+ characters with mix of letters, numbers, symbols
  • Different passwords for user and owner roles
  • Avoid personal information or common words
  • Consider using a password manager

Security Tips

  • Store passwords securely - we cannot recover lost passwords
  • User password: Required to open document
  • Owner password: Controls permissions (printing, editing, etc.)
  • Use PDF Sanitizer to remove metadata before encrypting

Frequently Asked Questions

Yes, 256-bit AES (Advanced Encryption Standard) is the highest level of encryption available for PDF files and is considered extremely secure:

  • Used by governments and banks worldwide
  • Approved for classified information up to "TOP SECRET" level
  • Currently no known practical attacks against AES-256
  • Same encryption standard used in HTTPS, VPNs, and encrypted messaging
  • Requires the password to decrypt - no backdoors or master keys

PDF encryption supports two different password types with distinct purposes:

  • User Password (Required): Required to open and view the PDF document. Without this password, the file cannot be accessed at all.
  • Owner Password (Optional): Controls permissions and restrictions. When set, you can restrict printing, copying, editing, or commenting.
  • Without Owner Password: No restrictions applied - users with the user password can do everything
  • With Owner Password: Users need owner password to change permissions or remove restrictions

No, PDF encryption with 256-bit AES is designed to be secure and irreversible without the password:

  • We do not store or have access to your passwords
  • There is no "forgot password" recovery option
  • The encryption happens locally in your browser
  • Always keep a backup of unencrypted files or store passwords securely
  • For lost passwords, try our PDF Decryption tool if you remember the password

No, encryption only adds a security layer without altering the document content:

  • All text, images, and formatting remain unchanged
  • No quality loss or compression applied
  • File size increases slightly (typically 1-5KB) for encryption metadata
  • Bookmarks, links, and form fields remain functional
  • Encrypted PDFs are 100% compatible with Adobe Reader and other PDF viewers

This tool encrypts one PDF at a time. For batch processing, you have several options:

  • Use the tool repeatedly for multiple files
  • Combine files first with our Merge PDF tool, then encrypt the combined file
  • For advanced automation, consider desktop PDF software with batch processing
  • All files processed separately maintain individual security settings

Related PDF Security Tools

Decrypt PDF

Remove password protection

Sanitize PDF

Remove metadata & hidden data

Remove Restrictions

Bypass usage limitations