How do I decrypt a password-protected PDF on OSX?

Question

I have a PDF that requires a password to view. I know what the password is. I frequently open this PDF to print it, and find entering the password each time incredibly annoying. How can I remove the password from the PDF?

Since I need to print it, simply taking a screenshot isn't a good solution.

I tried printing the file to a PDF, but Preview disables the "Save as PDF..." option in the print dialog.

Answer 1

Nathaniel's answer inspired me decide to try File/Save As... in Preview, which let me save a copy of the PDF with no password.

I'm surprised that it was that straightforward, but it worked.

Answer 2

There's a command-line tool called qpdf that can remove the password encryption from your PDF files, even in cases where Preview won't let you save a copy of or export the PDF.

Installing with Homebrew

1. Install Homebrew if you haven't already.

2. Install qpdf on your system by typing the following in Terminal:

   brew install qpdf
   

Installing with MacPorts

1. Install MacPorts if you haven't already.

2. Install qpdf on your system by typing the following in Terminal:

   sudo port install qpdf
   

Usage

Once qpdf is installed, use it to decrypt the file by typing the following in Terminal:

qpdf --decrypt --password=xxxxx encrypted-filename.pdf decrypted-filename.pdf

You can then open decrypted-filename.pdf in Preview to verify that it worked!

Answer 3

For those looking for a loop hole to save password protected PDF's in OS X 10.8.3 ... I found Opening the PDF in Chrome then Printing it to PDF using the Chrome dialog did the trick.

Answer 4

You would likely need Acrobat Pro to remove it, if you can open it, are you able to print it to PDF?

Answer 5

I did not find that Bobby Brant's solution worked on either 10.7.4 (the only 10.7 version I had available) or 10.8.2.

What I did find worked (most likely a loophole) was that I could export the file to TIFF (which created a massive 250MB file) and then print the tiff to PDF (which created an only slightly less awful 8MB file) --- all this from a 400kB original. Obviously the end result of this is a bitmap for each page, not a "real" pdf.

Answer 6

There are two types of protection and password, one for opening, and one for printing, editing and copying.

The first type of password is called Open Password or User Passwords. With this password, the whole file is encrypted. Without knowning the password, you cannot open it, not to mention printing, editing or copying. The file is totally useless to you. You can only crack it by brute force, which will takes you months to hundreds of years to get back the password. The length of time depends on the power of your computer and the complexity of the password. This article will NOT tell you how to unlock Open Password protected PDF files.

The second type of password is called Owner Password. If you want to turn off protection for printing, editing and copying, you will be asked for this password. Technically speaking, the protection for printing, editing and copying is just a number of bits of flags. You can turn off these flags without knowing the Owner Password. All software SHOULD (not MUST) ask for Owner Passwords if someone want to change the protection flags. This is why we can unlock PDF files for printing, editing and copying without asking for a password.

Obviously, you belong to the second case, so it would be quite easy to remove the password and print the secured PDF.

By the way, Adobe Acrobat does help you. But it is quite expensive. It takes you $449 for full version of Adobe Acrobat Pro and $299 for Adobe Acrobat Standard for lifetime.