Protect PDF
Add a password and AES-128 encryption to your PDF, entirely in your browser. Your file is never uploaded anywhere.
Beta feature — please verify before relying on it
This tool encrypts your PDF using the standard AES-128 PDF security handler. Before sending a protected file for anything important, we recommend re-opening it yourself first to confirm your PDF reader correctly asks for the password.
Drop your PDF here
Or click to browse from your computer
Frequently Asked Questions
What encryption does this use?
AES-128, using the PDF standard's "Revision 4" security handler — the same category of encryption used by most desktop PDF software. Key derivation happens locally in your browser using the algorithm defined in the PDF specification.
Is my file uploaded anywhere?
No. The entire encryption process — including the password itself — runs locally in your browser. Nothing is ever sent to a server.
What happens if I forget the password?
There is no way to recover a lost password — that's the whole point of encryption. Keep it somewhere safe, like a password manager.
Why is this marked as "beta"?
PDF encryption involves a fairly intricate binary specification. While this tool follows that specification closely, we recommend confirming your protected file opens correctly in your usual PDF reader before relying on it for sensitive documents.