How to use Protect PDF
- Drop one or more PDF files on the page. Files labelled “Ready” can be protected.
- Under “Password to open”, type the password twice. A bar shows how strong it is.
- Optionally open “Permissions” to limit printing, copying, editing, comments, form filling or page changes, and set an owner password.
- Click “Protect file(s)”, then download each file or “Download all as ZIP”.
Supported formats
Input: PDF files without existing protection, several at once. Output: an AES-256 encrypted copy of each file named <name>.protected.pdf; several files can be downloaded together as protected-pdf.zip.
Limits
Files that already have a password or restrictions are not protected again: remove the existing protection first with Unlock PDF. The same password and permissions apply to every file in the batch, and very large files depend on your device’s memory.
Privacy
Everything runs in your browser: your files are never uploaded to a server, and there is no sign-up.
Frequently asked questions
How strong is the encryption?
Files are encrypted with AES-256, the strongest method in the PDF standard. It needs a reasonably recent PDF reader, such as Adobe Reader 9 or later, a web browser or a current PDF app.
Can I block printing or copying without a password to open?
Yes. Untick “Require a password to open the file” and choose the restrictions under “Permissions”. Keep in mind that restrictions are a request to PDF software and some programs ignore them; for confidential files, use a password to open.
What is the owner password for?
The owner password is needed to change the permissions later and must differ from the password to open. If you leave it empty, a random 24-character password is created and shown once with a copy button.
What if I forget the password?
The file cannot be opened again: nobody, including MiniTools, can recover the password. Store it somewhere safe and keep an unprotected original if you may need it.
Is my PDF uploaded to a server?
No. Encryption runs in your browser, so your files and passwords stay on your device and are not saved anywhere.