Protect PDF
Add password protection to PDF
What is Protect PDF?
PDF Protect adds password encryption to a PDF document, preventing unauthorized access or modifications — essential for securing sensitive information before sharing.
When to use this tool
- Password-protecting a confidential report
- Encrypting a financial document before emailing
- Restricting editing permissions on a shared PDF
- Securing personal documents stored in the cloud
How it works
Applies AES-256 encryption to the PDF using pdf-lib, setting both an owner password (controls permissions) and a user password (required to open). Supports restricting printing, copying, and editing.
Security Guidelines
- Use a strong password — avoid common words or patterns
- Remember the password — encrypted PDFs cannot be recovered without it
- For maximum security, use both owner and user passwords with different values
About Protect PDF
Add password protection to PDF It runs entirely in your browser — no files are uploaded to any server, ensuring complete privacy and instant results.
- •Merge, split, and rotate PDF pages
- •Add watermarks and page numbers
- •Convert PDFs to text or Markdown
- •Sign and protect PDFs with passwords
Last updated: 2025-01-15
FAQ
Add password protection to PDF
Yes, completely free. No signup required.
Yes. Runs entirely in your browser, no files uploaded.
Yes, works on any device with a modern browser.
No, everything runs in your browser.