Protect PDF
Add an open password (limited). 100% in your browser — your file never leaves your device.
Nothing is uploaded — we explain real encryption instead of faking a weak lock.Files are processed on your device only. We never upload or store them. Some conversions (Office, OCR, encryption) are best-effort and may not preserve full layout.
About this tool
Protect PDF is about restricting who can open a document by requiring a password. Adding encryption is genuinely useful when a file contains personal or financial details and you want a gate in front of it. We are honest about the limits of an in-browser tool: the pdf-lib engine we use does not apply strong open-password encryption, so we do not pretend otherwise. For reliable protection, your PDF reader (such as Acrobat) or office suite offers battle-tested encryption. This page explains the options and points you to a dependable method rather than shipping a weak lock that feels secure but is not. The principle we care about is real privacy, which starts with honest tooling. No file is uploaded here regardless, because we are not asking you to hand us anything to “protect.”
When a file is sensitive, a password is the obvious safeguard — but only a real one. Someone with a tax PDF wants it locked before storing it in the cloud. A business wants a salary document gated. A person holding medical paperwork wants a barrier in front of it. In each case the right move is genuine encryption from a tool built for it, not a flimsy stand-in that merely looks protected. We would rather tell you that than let you believe a file is safe when it is not. Because we never ask you to upload the document, nothing about “protecting” it here puts it at risk; the honest guidance is to use your desktop reader’s encryption. Privacy is served by candor, not by a lock that does not actually lock.
How it works & privacy
This tool does not upload your file. Because strong PDF encryption is not available from the in-browser library we use, we explain the recommended approach instead of faking a weak lock: open the PDF in a desktop reader that supports encryption and set an open password there. Your document stays on your device throughout.
FAQ
Can this tool password-protect a PDF?
Not with strong encryption — the in-browser library we use does not apply open passwords reliably. We recommend your desktop PDF reader’s encryption feature instead of a weak stand-in.
Is my file uploaded here?
No. We do not ask you to upload anything; the page only explains protection options, keeping your document on your device.
How should I actually protect a PDF?
Use a desktop reader that supports encryption, set an open password, and keep the password out of email. That gives real, tested protection.