Resources » Working With PDFs » Guide to Locking, Unlocking, Protecting, Unprotecting PDF Files

PDFs are versatile, easy to share, and can be used for just about anything. Therefore, oftentimes we use PDFs for sensitive information that we don’t necessarily want everyone to have access to. Fortunately, PDFs have multiple levels of protection depending on what kind of security you’re looking for.

Standard PDF protection allows anyone with access to use, but not edit, the document. This is good for when you need to distribute a document but don’t want people to edit it.

Password protection means you require the people accessing the PDF file to enter a password before they can view the file. You can also restrict the user’s ability to print, change content, or copy text from a PDF. You might do this for copyrighted materials, or if you’re worried about the information being distributed or tampered with. You can even lock all but a specific part of a PDF. This is particularly useful for things like proposals and contracts that require signatures or filled-in forms.

Certificate security is used in extreme cases where the most sensitive documents require more than password security. This involves encrypting the document and identifying specific recipients who can access it. A third-party security certificate service will encrypt and provide identity verification services. The PDF will be completely inaccessible to anyone not identified as having access. Examples of companies that offer this include Docusign, PandaDoc, Dropbox Sign, Zoho Sign, GetAccept and JotForm; however, there are many more companies that offer this service as well. Be sure to read consumer reviews before using.

While you won’t be able to set up certificate security on your own, you can password protect your PDFs on most Windows and Mac devices.

How to Lock a PDF with Mac and Windows

Password protection for PDFs using Apple computers

Mac devices have built-in password protection features that require the person accessing the PDF to enter a password in order to open the file. You can also require a password for the person to print, copy text, and add annotations.

Using the Preview app, open the PDF you want to protect. Then choose File > Export. If you want a separate version of the PDF to be encrypted, enter a new name for the PDF.

Select the Permissions tab and then select one of the following:

  • Set password for opening the PDF: This will make users unable to open the document without a password.
  • Set permissions: You can select checkboxes next to the actions that you want to restrict. For example, you can require a password for printing or changing the document.

Enter a password in the Owner Password section. There may also be a box that says Encrypt that you can select for an extra layer of security. Then click apply and save the document.

Password protection for PDFs using Windows computers

To password protect a PDF, you’ll need to use an external password-protect tool like Adobe Acrobat. Adobe’s Password Protect feature allows you to create a password that a viewer will need to enter before they can view your PDF. Adobe’s password protection tool is easy to use. 

If you don’t want to use a third-party tool, Windows devices can use Microsoft Word to password-protect a document. Open the document in Word. If the document is a PDF, the Word will automatically convert the PDF into an editable .doc or .docx, but there may be formatting issues. You can use a PDF-to-Word converter to get a clean PDF without formatting issues. 

Using Word, select File and then Export and then select Create PDF/XPS. You can select Options at the bottom of the window that appears, prompting you to name and choose a location to save the PDF. In the options window, enable Encrypt the document with a password, which will then prompt you to enter a password.

When you’re done, select Publish, and the document will be saved as a Password encrypted PDF file.

Note that there is a slight difference between password protection and encryption. Encryption scrambles and hides the data until a password is entered, meaning it will be obfuscated even further. This is useful for more sensitive information, as password protection will only hide the document until you enter a password. It’s a good extra level of security, but not always necessary.

Both of the above options have encryption built in.

How to Unlock a PDF

If you’ve created a password-protected document but, for whatever reason, no longer need a password on it, it’s fairly easy to remove. Here are some options for unlocking or removing a password from a PDF.

Assuming you have the password, you can enter it to view the document and open it on your PDF viewer of choice. Then, select Print and save a duplicate copy of the new PDF. If you’ve selected printing or viewing encryption when securing the document, you will be unable to do this.

If you have your printer settings restricted, you’ll need to open the PDF on an app like Adobe Acrobat, where you can edit the security permissions of a PDF. To do this, go to Permission Details or the Document Properties sections and select the Securities tab. In this, you’ll see your document has Password Security as the security method. You will need to change this to No Security. Then, save the document.

Even if you’re not using Adobe Acrobat, most PDF viewers will have a security section where you can change the security settings of a document to remove a password. Note that this works only if you have the password; you shouldn’t hack a locked PDF. 

While you should never try to get into a PDF that you weren’t officially given access to, losing the password for a document can be a legitimate issue. If you lose the password for a secured PDF, you may need to search for a PDF password cracker. These services may, after some time, open up your PDF to remove the password and view it online. These services range in credibility and take a lot of time to crack a PDF, so it’s important to write down the password or use an easy-to-remember password for your documents!