About Protect PDF
A password stops anyone who intercepts or finds a PDF from opening it. This tool encrypts PDFs with 256-bit AES, the strongest standard PDF encryption, using the open-source QPDF library. You can also choose whether people who open the file may print it, copy its text or edit it. Share the password separately from the file, for example by phone or another app. Choose a long password that's hard to guess, because a strong password matters more than anything else. Keep a copy of it somewhere safe: a forgotten password can't be reset.
How to Use It
- 01
Add a PDF
Drop a PDF into the box, or tap to choose it.
- 02
Set a password
Type the password twice and choose what people may do once it's open.
- 03
Download
Press Protect PDF and download the encrypted file.
Questions
How strong is the protection?
The file is encrypted with 256-bit AES. With a long, unique password it cannot practically be opened without the password.
What if I forget the password?
It can't be recovered, by us or anyone else. Keep the original unprotected file or store the password in a password manager.
Do the print and copy restrictions always work?
Most PDF apps respect them, but they are a request rather than a lock. Some tools ignore them. The open password itself is enforced by encryption.
Is my password sent anywhere?
No. The password is used only by your browser to encrypt the file.