How do I remove a usage restriction from a PDF file?

Question

I have made usage restrictions to a PDF file and protected it with a password. Now I would like to remove the protection to allow my self to do more with the document. Doing a Google search for "unlock protected pdf with password" gave me all sorts of crazy suggestions using all sorts of cracking/hacking/illegal tools.

So I refined my search and included "adobe support" and found the following page.

Removing Security from PDFs: Individually and in Batch

This is where my problems would have ended but my version of Adobe Acrobat doesn't match the version used in the description. Also, my Security tab of the Document Properties dialog box (i.e. security properties) does not have the security options as shown in the example.

This is their:

And this is mine:

So how do I do this? Do I really have to hire a hacker for a day? Just to perform this simple task of unlocking the restrictions of my own document? I mean I know the password... hell, I thought Adobe software would be smarter than this.

I previously had the older version of Adobe Acrobat as the one shown in the example (see screenshot and link above) and I know that it was possible to remove this restriction very easily. There was even a dedicated button for this on the toolbar.

This is the Security button in old Adobe Acrobat:

For the record, I have Adobe Acrobat X Pro.

Answer 1

Try QPDF

I did not want to upload my PDF to a dodgy site and wait in queue, so instead I spent some time googling. I found this free open source utility called qpdf.

I ran it on the file like this:

qpdf --decrypt input.pdf output.pdf

And the restrictions were removed. Note that the original PDF was not password protected.

Alternatively, if you prefer to overwrite the input file instead of specifying an output file, you can use the --replace-input option, like so:

qpdf --decrypt --replace-input input.pdf

This will remove the restrictions and replace the original input.pdf with the decrypted version.

Further reading

• From the QPDF manual: Rationale for not enforcing restrictions
• List of possible PDF restrictions: QPDF manual, section 3.3: Encryption Options

Answer 2

PDFUnlock! "Remove passwords and restrictions from secured PDF files!"

Answer 3

• upload to google drive (with chrome)
• hit the print button
• save as pdf

I get the real deal, images are same resolution, file size checks out too, but all the security restrictions are gone.

Thanks Google! You guys are hackers :-)

P.S.: Sometimes the "save as pdf" option needs to be enabled in chrome.

P.P.S.: As @Gabriel Luci points out, some special functions will not get converted properly, including any "active" content that uses scripting and some form features.

Answer 4

I was also trying to bypass PDF permission password security. I have received this file from my client and he said he forgot the password. I did a quick Google search and found the website PDFUnlock but I didn’t upload the PDF file there because this PDF file is pretty confidential and this PDFUnlock website looks quite phishy. I mean in the header area there is a hyperlink that redirects to some fundraising/donation website, then there is “Purchase PDF Unlocker” button and again in the end there is a “Donate” button that redirects to PayPal. Note: It’s just my personal opinion.

Then I came across to this guide to removing PDF password security/restrictions. Program mentioned here did the job for me! It’s not free but it works perfectly. Now I can easily print, copy and modify this PDF file.

P.S. My PDF file was protected with 256bit encryption.

Update: I just discovered that Instructable tutorial link that I posted in my answer is dead so I replaced it with the website link from where I downloaded the program.

Answer 5

My mistake! Ever since I installed Adobe Reader (Adobe Acrobat Reader) PDF files are opening in Adobe Reader by default, not in Adobe Acrobat Pro! I need to change this.

These options are not available in Adobe Reader, they are only available in Adobe Acrobat (Pro version). So with the PDF file opened in Adobe Acrobat program the official instructions should work.

You can remove security from an open PDF if you have the permissions to do so. If the PDF is secured with a server-based security policy, only the policy author or a server administrator can change it.

1. In the open PDF, do one of the following:
   • Select Tools > Protection > Encrypt > Remove.
   • In the Security tab of the Document Properties dialog box, choose No Security from the Security Method menu.
2. Your options vary depending on the type of password security attached to the document:
   • If the document only had Document Open password, click OK to remove it from the document.
   • If the document had a permissions password, type it in the Enter Password box, and then click OK. Click OK again to confirm the action.

Source: Securing documents with passwords

Now this is what the Document Properties dialog box looks like when I open the same document in Adobe Acrobat X Pro: