How to password-protect a PDF
- Add a PDF.
- Enter a password and confirm it, and choose any restrictions.
- Select Protect PDF, then download.
About this tool
PDFPUMA encrypts your PDF with 256-bit AES, the strongest encryption in the PDF standard, using the open-source qpdf engine running in your browser. Anyone opening the file will need the password.
You can also restrict printing, copying and editing. These permission settings are honoured by mainstream PDF apps, but they aren't a strong security boundary on their own — the open password is what actually protects the contents.
PDFPUMA never sees or stores your password. If you forget it, the file can't be recovered by us or anyone else, so keep a copy of the original.
Frequently asked questions
Are my files uploaded to PDFPUMA?
No. This tool runs entirely in your browser. Your files are read and processed on your device and the result is created there too — they are not sent to PDFPUMA's servers.
Which encryption does PDFPUMA use?
AES with a 256-bit key (PDF 2.0 / Acrobat X and later). It opens in every modern PDF reader.
What if I forget the password?
We can't recover it — the password never leaves your device. Keep the unprotected original somewhere safe.
Which plan includes Protect PDF?
Protect PDF is included in Starter, Business and Agency.