Add to Chrome

How to password-protect a PDF for free, without Acrobat

By the Docmend team · Updated · 3 min read

Short answer

You don’t need Acrobat. On a Mac, open the PDF in Preview, choose File > Export, click Permissions and set a password. In Word, save as PDF and tick “Encrypt the document with a password.” On any computer, Docmend’s free Protect PDF tool adds a password in your browser without uploading the file.

Docmend (docmend.app), a Chrome extension and free document tools site, makes the Protect PDF tool used below.

Pick the method that fits

Protect a PDF in your browser with Docmend

  1. Open Protect PDF and choose the PDF.
  2. Type a password twice and choose whether people can print or copy text.
  3. Click “Protect with password” and save the new copy.

The tool uses AES-256 encryption and runs in your browser, so the PDF never leaves your computer. Docmend never sees or stores the password, which also means nobody can recover it for you. Write it down somewhere safe before you send the file.

Protect a PDF with Preview on a Mac

Apple’s Preview guide lists these steps:

  1. Open the PDF in Preview and choose File > Export. Give it a new name if you want to keep an unprotected original.
  2. Click Permissions and select Require Password To Open Document. Enter the password and retype it.
  3. Choose which actions, such as printing or changes, need the owner password, then enter an owner password.
  4. Click Apply, then click Save.

Apple notes that the changes take effect the next time someone opens the PDF.

Protect a PDF with Microsoft Word

If the document started in Word, add the password as you export it:

  1. Choose File > Save As (or Save a Copy) and pick PDF as the file type.
  2. Click Options and select “Encrypt the document with a password.”
  3. Click OK, type the password twice in the Encrypt PDF Document box, and save.

Microsoft says this option restricts access so only people with the password can open the PDF.

Protect a PDF with LibreOffice

Open the document in LibreOffice, choose File > Export As > Export as PDF, open the Security tab and click Set passwords. You can set a password to open the file, a permissions password, or both. LibreOffice’s help warns that only PDF readers that follow version 1.5 of the format respect the permission limits, so older readers may ignore them.

Open password vs. permissions password

An open password stops anyone without it from opening the file. A permissions password (Apple calls it the owner password) lets people open the PDF but limits printing, copying or editing. If the content is private, use an open password. Permission limits only stop people whose PDF reader respects them.

Send the password the safe way

Don’t put the password in the same email as the PDF. If someone gets into that inbox, they get both. Share it by phone, text or another channel instead. To remove the password later, use Unlock PDF with the password you set.

Common questions

Can I password-protect a PDF without Adobe Acrobat?

Yes. Preview on a Mac, Microsoft Word, LibreOffice and Docmend’s Protect PDF tool can all add a password for free. Each one saves a copy of the PDF that asks for the password before it opens.

Is it safe to protect a PDF with an online tool?

It depends on whether the tool uploads your file. Docmend’s Protect PDF runs in your browser, so the PDF and the password stay on your computer. Read a tool’s privacy notes before you use it for private documents.

What if I forget the password?

Docmend can’t recover it, because the tool never sees or stores the password. Keep the original unprotected file or write the password down somewhere safe.

Can I stop people from printing or copying a PDF?

Yes. Docmend’s Protect PDF lets you choose whether people can print or copy text, and Preview and LibreOffice offer similar permission settings. Some PDF readers don’t follow these limits, so don’t rely on them for secrets.

How do I remove a password from a PDF?

Open Docmend’s Unlock PDF, type the password and save a copy that opens without it. If the PDF opens but blocks printing or copying, leave the password empty. The tool can’t open a PDF if you don’t know the password.

Sources

Related guides