How to Protect PDF with Password Online Free

Password-protect any PDF document online to keep sensitive information secure — completely free.

Password-protecting a PDF ensures only authorised recipients can open and read it. This is essential for sensitive business documents, confidential reports, legal contracts, and personal financial records.

Types of PDF Protection

  • Open password: Requires a password to open and view the PDF
  • Permission password: Allows viewing but restricts printing, copying, or editing
  • Both: Maximum protection — requires a password to open AND restricts further actions

How to Protect PDF with Password Free

Visit imgresizr.com's PDF Tools section and upload your PDF. Enter a strong password (at least 12 characters mixing letters, numbers, and symbols). Choose whether to restrict only opening or also restrict printing and copying. Click Protect and download your password-protected PDF. Share the PDF and the password to recipients separately — never in the same message.

Password Strength Guidelines

PasswordSecurity Level
Less than 8 charsWeak — avoid
8–11 chars mixedModerate
12+ chars mixedStrong
20+ charsVery strong

Important Security Notes

  • Never share the password in the same email or message as the PDF
  • Use a different communication channel for the password (e.g., SMS, phone call)
  • Keep a record of passwords for protected PDFs you create
  • PDF encryption is strong but not unbreakable — do not rely on it for classified government material
  • Some tools and services can remove PDF passwords — protection works best as a deterrent

Protect PDF files with passwords for free at imgresizr.com — add security to any PDF document instantly.