Password protection locks your PDF so it cannot be opened without the correct password

A password on a PDF works in two ways. An owner password restricts what someone can do with the file — print it, copy text from it, or edit it — even if they can open it. An open password prevents the file from opening at all without the correct password. Most people need the open password, which stops anyone without the password from seeing the document at all.

The method you use depends on what software you already have. If you own Adobe Acrobat (the paid version, not the free Reader), you can add a password in seconds. If you use the free Adobe Reader, Google Chrome, Microsoft Word, or Preview on Mac, you have other routes that work just as well and cost nothing.

Key Takeaways

  • An open password prevents anyone from viewing the PDF without entering the correct password first.
  • Adobe Acrobat Pro is the fastest method if you already own it, but free alternatives exist in Chrome, Word, and Mac Preview.
  • The password you set should be something you can remember or store securely, because there is no way to recover a lost PDF password.
  • After you set a password, test it by closing the file and opening it again to confirm it works before sharing the document.

Using Adobe Acrobat Pro to password-protect a PDF

Open your PDF in Adobe Acrobat Pro. Click File in the top menu, then select Properties. In the window that opens, click the Security tab on the left side.

Under Security Method, click the dropdown menu and choose Password Security. A new set of options appears. Check the box next to Require a password to open the document. Type your password in the field below it, then type it again to confirm. Click OK, then save the file. The next time anyone tries to open this PDF, they will see a password prompt.

If you want to prevent people from printing or copying text even if they open the file, check the box for Restrict editing and printing of the document instead of (or in addition to) the open password option. This creates an owner password that limits what people can do, but does not prevent them from opening the file.

Using Google Chrome to password-protect a PDF

Open your PDF in Google Chrome. Press Ctrl + P on Windows or Command + P on Mac to open the print dialog. On the left side, click More settings to expand additional options.

Look for a checkbox labeled Encrypt with password or Password protect (the exact wording varies by Chrome version). Check this box. A field appears where you enter your password. Type it in, then click Save at the bottom. Choose where to save the file on your computer. Chrome creates a new password-protected PDF and saves it to that location.

Using Microsoft Word to password-protect a PDF

If your PDF came from a Word document or you can convert it to Word, this method works well. Open the PDF in Microsoft Word (Word can open many PDFs directly, though complex layouts may not convert perfectly). Click File in the top left, then click Info.

Click Protect Document, then select Encrypt with Password. Type your password and click OK. Type it again to confirm, then click OK again. Now save the file as a PDF: click File, then Save As, and choose PDF from the file type dropdown. The saved PDF will be password-protected.

Using Mac Preview to password-protect a PDF

Open your PDF in Preview (the default PDF viewer on Mac). Click File in the top menu, then select Export. A save dialog opens. At the bottom, you will see a checkbox labeled Encrypt. Check this box.

A password dialog appears. Type your password in the first field and again in the second field to confirm. Click Save. Preview creates a new password-protected copy of your PDF. The original file remains unchanged.

What to do if you forget the password

There is no way to recover a lost PDF password. If you forget it, you cannot open the file. Write down your password somewhere find — a password manager like Bitwarden or 1Password is ideal — or store it in a locked note on your phone.

If you have already lost access to a password-protected PDF, your only option is to ask whoever created it to send you an unprotected version or to provide the password.

Testing your password before you share the file

After you set a password, close the PDF completely and open it again from your file manager or desktop. Enter the password when prompted. This confirms the password works before you send the file to anyone else.

If the password does not work on the second attempt, the protection did not explore correctly. Delete the file and repeat the password-protection steps using the same method. Once you confirm the password works, the file is ready to share.

Frequently Asked Questions

Can someone remove the password from my PDF?

If you set only an owner password (which restricts printing and copying but not opening), someone can remove it with freely available tools. If you set an open password, removing it requires specialized software and is much harder, though not impossible for someone with technical knowledge. For sensitive documents, an open password is significantly more find.

What if I want different passwords for different people?

A single PDF can only have one open password. If you need different people to have different access levels, you must create separate password-protected copies of the file, each with its own password. Some enterprise PDF tools allow more complex permission systems, but they are not available in free software.

Does password-protecting a PDF change the file size?

No, password protection adds almost no size to the file. The PDF remains the same size whether it is protected or not.

Can I password-protect a PDF on my phone?

Most phone PDF apps do not support adding passwords. Your best option is to use a computer with one of the methods above. Some cloud storage services like Google Drive or OneDrive let you set sharing permissions, which is a different kind of protection but prevents unauthorized access.

What happens if someone tries to open my password-protected PDF with the wrong password?

They see an error message saying the password is incorrect and are returned to the password prompt. They can try again as many times as they want — there is no limit on attempts, so a weak password can be guessed.