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Protect PDF — free online tool
Add a password to a PDF with strong AES-256 encryption so only people with the password can open it. It runs entirely in your browser — your files never leave your device, and it's completely free with no signup.
- AES-256 password protection
- Keep sensitive documents private
- Free, runs locally
How to protect pdf
- 1Upload the PDF you want to protect.
- 2Set a password.
- 3Click Encrypt PDF and download the protected file.
Frequently asked questions
How strong is the encryption?
Files are encrypted with AES-256, the same standard used by banks.
What if I forget the password?
There's no recovery — store your password safely, as it's required to open the file.
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