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Protect PDF

AES-256Beta

Add an open password to a PDF with AES-256 encryption and optionally block printing, copying and editing. Runs in your browser; nothing is uploaded.

Files are not uploaded · processed in your browser

PDF file
or drop files here (files are processed locally, never uploaded)

Needed to open the file. It cannot be recovered if forgotten.

Permissions (optional)

Uncheck to block. Restrictions rely on the viewer and cannot stop special tools.

Choose a PDF, enter the password twice, then click "Protect PDF".

How to password protect a PDF

  1. Choose or drop the PDF you want to protect.
  2. Enter an open password and type it again to confirm.
  3. To block printing, copying or editing, uncheck those permissions.
  4. Click “Protect PDF” and download the encrypted file. Keep the password safe; it cannot be recovered.

Privacy

Files you choose and text you enter are processed in your browser. They are not uploaded to our servers and we do not store them. Some tools download the code or data they need (such as OCR language data) from this site the first time you use them.

Read the privacy policy

FAQ

Are my PDF and password uploaded?

No. Encryption happens in your browser. The file and password never leave your device and are not stored.

Which encryption is used?

Always AES-256, the strongest encryption in the PDF standard. It opens in Adobe Acrobat, Chrome, Edge, Safari, macOS Preview and other common viewers.

What if I forget the password?

The file cannot be opened. AES-256 cannot be cracked and we never store your password, so keep it somewhere safe.

Are print, copy and edit restrictions guaranteed?

Restrictions rely on the PDF viewer honoring them. Mainstream viewers do, but special tools can bypass them; the open password is the real protection. When you set restrictions, the permissions password is generated randomly in your browser, so people who only know the open password are restricted too.

Can the password contain non-English characters?

Yes, up to 127 bytes (1 byte per Latin letter, usually 3 per CJK character). Full-width letters and digits are treated as half-width, matching Acrobat. Letters and digits are easiest to type on every device.

Can I re-protect a PDF that already has a password?

Remove the old password with Unlock PDF first, then set a new one.

Can I set the password on my phone?

Yes. Encryption runs in your phone's browser with nothing to install, so neither the file nor the password leaves the device. Files up to 200 MB are accepted; a very large one may run out of memory on a phone, in which case use a computer.

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