How to use the Protect PDF tool
- Choose a PDF file.
- Type the password twice.
- Optionally choose what readers may do: print, copy text, edit.
- Click “Protect PDF” and download the encrypted file.
How the protection works
The file is encrypted with AES-256, the strongest method in the PDF standard, supported by Adobe Acrobat, browsers, macOS Preview and all modern PDF apps. Without the password, the content cannot be read, not even by opening the file in a text editor.
The tool uses qpdf, a widely used open-source PDF library, compiled to run inside your browser.
Permissions: printing, copying and editing
You can also set an owner password and turn off printing, copying or editing. Note that these permissions are a request to the PDF reader, not real protection: good apps respect them, but some tools ignore them. Only the open password truly protects the content.
Choosing a good password
Use at least 12 characters, or several random words. Send the password through a different channel than the file, for example the file by email and the password by phone or messenger. If you lose the password, nobody can recover the document, including us.
Privacy
Everything runs in your browser. Your files and text are not uploaded to our server or stored anywhere.
Frequently asked questions
Which encryption is used?
AES with a 256-bit key (PDF 2.0 / Acrobat X level). It is the strongest encryption PDF supports.
Can I remove the password later?
Yes. Use the Unlock PDF tool and enter the password once to save an unprotected copy.
Do you see my password?
No. The password and the file stay in your browser. Nothing is uploaded.
Will the PDF open on phones?
Yes. All current PDF readers on Android, iPhone, Windows and Mac support AES-256 encrypted files.