Add Password to PDF
Choose a password and download a copy of your PDF that can't be opened without it.
Leave this blank if you only want to restrict printing/copying/editing below - the PDF will then open for anyone with no password prompt, but a compliant reader still enforces the restrictions you pick.
Restrict what a reader can do (optional)
These discourage casual printing/copying/editing in compliant PDF readers - they are not strong DRM. A determined person using different software can often bypass them, so don't rely on this alone to protect anything sensitive.
Questions fréquentes
What encryption does this actually use?
The PDF's standard security handler, revision 4, with AES-128 in CBC mode encrypting every string and stream in the file - the same open-password scheme most PDF software has supported for years. It's genuine, spec-compliant AES-128 encryption, not a toy scramble: it was verified by encrypting a test file and independently opening it with pdf.js (a completely separate PDF engine from the one that wrote it), confirming it correctly refuses the file without the password and correctly opens it with the right one. That said, PDF's standard security handler - even at 128-bit AES - is decades-old and not treated as high-security by modern standards; it stops casual access, but a determined, well-resourced attacker with specialized tools can still work around passwords on any PDF encrypted this way (or with any consumer PDF tool). Don't rely on it alone for highly sensitive documents.
Does this happen in my browser, or on a server?
Entirely in your browser. The PDF is read, encrypted and rebuilt on your device using the Web Crypto API for the actual AES encryption - neither the file nor the password you choose is ever uploaded anywhere.
Can I set a separate password to just restrict printing/editing, but let anyone open it?
Not with this tool - it only sets a single password required to open the file at all (both the "user" and "owner" password fields inside the PDF are set to what you type here). If you need permission-only restrictions with no open password, that's a different feature this tool doesn't offer.
What if I forget the password?
There is no recovery. The password isn't stored anywhere - not on a server, not in the file itself in readable form. If you forget it, the PDF can't be reopened by this tool, by us, or (short of specialized password-recovery software) by anyone else either.
Will this work on a PDF that's already password-protected?
No - it only encrypts PDFs that don't already have a password. If your file is already protected, use Remove PDF Password first with its existing password, then add a new one.