PDFDEN / Security / Protect PDF

Password Protect PDF

Password protect PDF files so only people with the password can open them. Encryption runs in your browser, so the unprotected file never leaves your computer.

or drop it here Processed on your device. Nothing is uploaded.

How to password protect PDF

Drop your PDF into the box.
Enter the password that will be needed to open the file.
Optionally restrict printing, copying or editing.
Run it and download the protected PDF.

Protect a PDF with a password

The file is encrypted with AES-256 using qpdf. Anyone who opens it needs the password you set.

Choose a password you can share safely, and send it separately from the file. For more on choosing settings, read how to password protect a PDF.

Restrict printing, copying and editing

Permissions add a second layer. You can block printing, stop text from being copied or prevent edits, while the open password still controls who gets in.

Keep a copy of the password. If you lose it, Unlock PDF cannot recover it. Planning to email the file? Compress it before you encrypt.

Guides

How to Password Protect a PDFHow to password protect a PDF with AES-256 encryption, and optionally block printing, copying or editing. Free, and the file never leaves your browser.How to Remove a Password From a PDFHow to remove a password from a PDF you can open: enter it once, save an unlocked copy. Free, runs in your browser, the file is never uploaded.How to Redact a PDFHow to redact a PDF so the hidden text is really gone: box it or search for it, burn it in, download. Free, and the file stays in your browser.How to Flatten a PDFHow to flatten a PDF so form fields and comments can no longer change, and what flatten PDF actually means. Free, runs in your browser.How to Sign a PDFHow to sign a PDF: draw, type or upload your signature, place it on the page, add the date, download. Free, no signup, nothing uploaded.

Frequently asked questions

How do I password protect a PDF?

Drop the PDF here, type a password and run it. The downloaded file asks for that password when opened.

What encryption does PDFDEN use?

AES-256, applied with qpdf in your browser.

Can I stop people printing or copying my PDF?

Yes. Turn on the restrictions for printing, copying or editing when you protect the file.

Is it safe to password protect a PDF online here?

The file and the password stay in your browser. Nothing is sent to a server.

What if I forget the password?

It cannot be recovered. Keep the original unprotected file or store the password somewhere safe.

How do I remove the password later?

Use Unlock PDF with the password. The remove password guide shows the steps.