Protect PDF.
Encrypt your PDF with an opening password using AES-256, entirely on your device.
Your documents stay on your device. No sign-up needed.
How to use Protect PDF
- 01
Choose an unencrypted PDF.
- 02
Enter and confirm a strong password with at least eight characters.
- 03
Download the encrypted PDF and store your password safely.
Finish the document, then encrypt it
Add an opening password after completing any merging, editing or form filling. The downloaded copy uses AES-256 encryption and requires a compatible reader and the password to open it. The original file stays unchanged. Follow the password protection guide to check the saved copy before sharing.
Frequently asked questions
Is this real PDF encryption?
Yes. The PDF is encrypted with AES-256 using qpdf compiled to WebAssembly. A compatible PDF reader requires your password to open it.
Can you recover my password?
No. We do not receive or store passwords or documents. Keep your password safely; we cannot recover it for you.
Is this PDF tool free?
Yes. All 15 tools are free to use without an account. Large or complex PDFs may exceed your browser’s available memory; try a smaller file or a computer if that happens.
Can I use password-protected PDFs?
Use Unlock PDF with a valid password first, if you are authorised to remove protection. These editing tools require an unencrypted PDF.