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Password protect a PDF, in your browser

Lock a PDF with AES-256 and choose what's allowed without the password. Runs on your device; nothing is uploaded.

Drop a PDF, or click to choose

Add a password to open it. Nothing is uploaded.

How to password protect a PDF

  1. Choose the PDF. Drop it above or click to pick it. Page 1 appears.
  2. Type a password. The locked copy is made as you type and checked straight away. Use the eye button to see what you typed.
  3. Choose what’s allowed (optional). Tap Printing, Copying text or Editing to turn it off, then set a separate permissions password.
  4. Download. The new file asks for the password before it shows anything. Your original is left as it was.

What the protection does

The PDF is encrypted with AES-256, the strongest method the PDF format defines (PDF 2.0, revision 6). Without the password, the pages, text and images inside the file are unreadable, not just hidden. After writing the file, the tool reads it back to confirm it refuses to open without a password, opens with yours, and carries the permissions you chose.

A password can’t be recovered if it’s forgotten, by this tool or anyone else. Keep a copy somewhere safe, and keep the original file too.

Open password and permissions password

  • The open password is what anyone needs to view the PDF at all.
  • The permissions password guards the restrictions. Someone with only the open password can read the file but cannot lift what you turned off.

Restrictions on printing, copying and editing are honoured by mainstream PDF readers, but they are instructions to the reader app rather than encryption of their own. For anything truly private, rely on the open password, and share it separately from the file.

Private by design

The encryption runs in your browser, using an open-source PDF engine that works on your device. The file and the password stay there and are never uploaded. Need to take a password off later? Use Unlock PDF with the password you set.

Sharing only part of a document? First delete the pages you want to keep back, or merge several PDFs into one and lock them together.

Common questions

How strong is the encryption?
AES-256, the strongest encryption the PDF format offers. Without the password the file's contents can't be read.
Is my PDF uploaded to add the password?
No. The encryption runs in your browser. The file and the password never leave your device.
What if I forget the password?
It can't be recovered, by this tool or anyone else. Keep the password somewhere safe and keep your original file.
Can I stop people printing or copying text?
Yes. Turn off Printing, Copying text or Editing and set a permissions password. Mainstream readers honour these restrictions, though they are rules for the reader app, so treat the open password as the real protection.
Will the PDF open in any reader?
Yes. AES-256 PDFs open in current desktop PDF readers, browser PDF viewers and the built-in viewers on phones and computers, once the password is typed.
My PDF already has a password. Can I change it?
Remove the old one with Unlock PDF, using the password you know, then add the new one here.
Is it free?
Yes. No sign-up, no watermark, and the original file is left untouched.