How to password protect a PDF on Windows

How to password protect a PDF on Windows with Deckle

1. Open Password protect PDF in Microsoft Edge, Chrome or Firefox.
2. Drag the PDF from File Explorer onto the page, or choose Select a file.
3. Type a password in Password. It must be at least 6 characters.
4. Type it again in Confirm password. A mismatch shows under the field as you type.
5. Choose Protect this PDF. The button stays disabled until both fields match.
6. Download the protected copy, which has "(protected)" added to its name.
7. Open it in Edge to confirm it asks for the password.

Before the result appears, Deckle checks that the new file refuses an empty password and opens with yours.

What the password protects

The password is needed to open the file in any PDF reader. Deckle encrypts with AES-256, the encryption used by current PDF readers. It sets one password for opening the file; it does not add separate restrictions on printing or editing.

Nobody can recover a forgotten password, including Deckle. Store it in a password manager before you delete the unprotected original.

To send the file, email the PDF and share the password by phone or text message, so one intercepted message doesn't open it. See how to share a password-protected PDF.

Save a password-protected PDF from Word

If you are creating the PDF from a Word document, the Windows desktop version of Word can encrypt it as it saves. Microsoft's page Save or convert to PDF or XPS in Office Desktop apps describes it:

1. In Word, choose File > Save a Copy (or Save As).
2. Choose PDF in the file type list.
3. Choose More Options, then Options, and select Encrypt the document with a password. Choose OK.
4. Enter the password twice in the Encrypt PDF Document box, then save.

These steps are for the desktop version of Word on Windows. For a PDF you received, or one made by a scanner or another app, use Deckle.

Choose a password that works

• Use at least 6 characters. Deckle won't accept fewer. Longer is better: a passphrase such as copper-violin-garden is easy to say on the phone and hard to guess.
• Don't reuse your Windows or email password. You will share this one.
• Agree a pattern with regular recipients. An accountant who receives monthly files may prefer one password per year, sent once by phone.

Tips

• Clear metadata before you lock the file. Protection keeps properties such as Author. Remove them first with Remove PDF metadata; see how to remove metadata from a PDF on Windows.
• Merge first. A protected PDF can't be merged. Combine files with Merge PDFs, then protect the result.
• Change a password in two steps. Unlock the file with Unlock PDF and the current password, then protect the unlocked copy with the new one.
• Don't protect files for online forms. Portals usually can't open them.

Frequently asked questions

How do I put a password on a PDF in Windows 11 for free?

Open Password protect PDF in Edge, set the password and choose Protect this PDF.

Is the password sent anywhere?

No. The PDF is encrypted in your browser and the password is not stored or uploaded.

Can I stop people printing the PDF?

Not with Deckle, which sets an open password only.

Can I protect several PDFs at once?

No. Protect each file in turn, or merge them first and protect the combined file.

What if I forget the password?

The PDF can't be opened without it, and Deckle keeps no copy. Keep the unprotected original until you have stored the password safely, then delete the original if it shouldn't be kept.

Related tools

• Password protect PDF to add an open password
• Unlock PDF to remove a password you know
• Remove PDF metadata to clear properties before locking