What encryption does this actually use?

Real AES-256 encryption via qpdf, the same open-source library used by many professional PDF tools — not a cosmetic password field that a basic PDF reader could ignore.

Does Documateo store my password?

No — the password is used only in memory during processing and is never written to any database or log. If you lose it, Documateo has no way to recover it, and neither does anyone else — that's what real encryption means.

Can I protect a PDF that's already password-protected?

Not directly — unlock it first with your existing password, then apply the new one.

Protect PDF

Pro

Add a real password to a PDF with AES-256 encryption — the same standard professional tools use, not a cosmetic lock.

How it works

1
Upload the PDF you want to lock.
2
Enter and confirm a password.
3
Documateo encrypts the file using real AES-256 encryption on our servers.
4
Download the password-protected PDF.

Protect PDF — frequently asked questions

What encryption does this actually use?: Real AES-256 encryption via qpdf, the same open-source library used by many professional PDF tools — not a cosmetic password field that a basic PDF reader could ignore.
Does Documateo store my password?: No — the password is used only in memory during processing and is never written to any database or log. If you lose it, Documateo has no way to recover it, and neither does anyone else — that's what real encryption means.
Can I protect a PDF that's already password-protected?: Not directly — unlock it first with your existing password, then apply the new one.