What Is a Document Open Password?

How to protect your PDF docs

A document open password is a password used to restrict the opening of a PDF file. In contrast, PDF owner passwords are used to provide document restrictions in PDF files.

While this password is called the document open password in Adobe Acrobat, other PDF programs may refer to this password as the PDF user password or the PDF document open password.

Screenshot of the Document Open Password prompt in Adobe Reader

How to Set a Document Open Password on a PDF

Some PDF readers may let you protect the opening of the PDF with a password but it's usually specialized tools that include that option. There are also some PDF creators that have the option of creating a PDF user password.

With tools that create PDFs, you normally have to start off with a file that isn't a PDF (since the idea is to create a PDF), and therefore aren't all that helpful if you're wanting to make a document open password for an existing .PDF file.

You can install the free trial of Adobe Acrobat to protect a PDF with a password, or of course, use the full version if you have it. Use the File > Properties menu and then the Security tab to find the Security Method option. Choose Password Security and then select the option in the new window called Require a password to open the document. Enter a password in that text field to create the document open password for the PDF file.

Two other options for adding a password to a PDF is to use the Soda PDF or Sejda website. They're very easy to use: upload the PDF file to the website and then enter the password you want to use.

The Password Protect PDF page on Smallpdf.com is a similar website where you can stop a PDF from opening unless the password of your choosing is entered. You can use two PDFs on their site per day without paying.

How to Crack or Remove a PDFs Document Open Password

Document open passwords aren't easily hacked but there are a few PDF password recovery tools that can do it via a brute-force attack, given enough time.

The website Smallpdf.com is one example. After attempting to remove the password for you, it will ask you to enter the password yourself if it doesn't succeed. Either way, it removes the password for you so that you can then download it back to your computer and use it as a regular PDF file.

Like you read above, Smallpdf.com can only deal with two PDFs per day, for free users. This means you can set a password on two PDFs, remove the user password on two PDFs, or do a combination of both, but only involving two files within each day.

To simply remove the password, you can open the document in Adobe Acrobat. It will, of course, make you enter the password before you can move forward, after which you can follow the same steps as described above for setting the user password, but by choosing No Security instead of Password Security.

While the Soda PDF website mentioned above is used for securing a PDF, the Soda PDF Unlock PDF page lets you remove the password. Unlike a PDF password cracker, you have to know the password. This website is useful if you're just wanting to remove the password protection.

  • How secure are PDF passwords?

    PDF passwords can be hard to crack if you create a strong password that's difficult to guess, or use a tool that encrypts the document and requires the user to enter a private key. Adobe Acrobat Pro PC offers this extra layer of privacy along with additional safeguards such as encryption certificates, printing restrictions, and editing restrictions.

  • Can I add password protection to PDFs for free?

    Yes, you can password-protect PDFs for free. In addition to online programs like smallPDF.com, Microsoft Word and Preview come with built-in password protection. In a Preview document, select File > Export > Encrypt and enter a password. In Word, save the document as a PDF > Options > select Encrypt the document with a password, or Export as PDF > Show Details on a Mac.

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