Is there a way to unlock PDF documents?

Question

I realize most PDF documents are locked for a reason, but I spend several hours a week editing datasheets provided directly from my vendors to be sent to customers. Obviously it's very annoying and somewhat of a show-stopper when I download a datasheet in PDF format, then I am not able to draw boxes, add comments, or draw arrows to the supplied product.

One of our vendors told us the way around that was to print a physical copy, then scan it in as a PDF - not the most technological or aesthetically pleasing solution I have found.

I at least would like to be able to print the PDF to another PDF so that the new copy is unlocked for editing. Is there any way around this?

Answer 1

I know this might not the solution you're looking for, but I'll try my luck...Okular has the option to ignore any DRM-Settings of a PDF-File.

Answer 2

I tried a few solutions above, but they were unsatisfactory. "Print To PDF" using CutePDF for instance produces an image. I don't want an image.

I ended up using ILovePDF->Unlock PDF. It is online, but worked a treat. I am not associated with it.

Answer 3

Assuming that you know the Password to the PDF, the most simplest method would be:

• Open the PDF in a Browser by putting in pwd (like Chrome or any application that can read it natively and can print it as well)
• Print the document (CTRL + P or Cmd + P, usually). But in the Print dialog, choose to Save as PDF, instead of actually printing

Done.

PDFTK can help you create shell commands as a Service, or a Workflow in Automator in Advanced OSs like Mac, so that you just right click a PDF and say "Unlock this PDF"

Refer this SO question for above

Answer 4

The missing ANSWER has been and still currently is a File transformer such as qpdf.

QPDF is a software library and a free command-line program that can convert one PDF file to another equivalent PDF file. It is capable of performing transformations such as linearization (also known as web optimization or fast web viewing), encryption, and decryption of PDF files

It attempts to keep as much of the source file as possible (unlike re printing or online services that dont use it). Same as any other method if there are encrypted signatures they will naturally become invalid.

There are various derivatives of the C++ by others such a Tqpdf for Delphi or Pyke for Python.

The only limitation is that like EVERY other solution it might need any "opener" password since that it what makes a "locked" PDF file un-scrambled into a readable optionally secured PDF.

The "Usage" password is a hard to crack (takes years) double onion skin around the internal owners optional DRM encryption.

Thus to remove the internal scrambling, use something like:

qpdf --decrypt adobe-secured.pdf qpdf-decrypted.pdf 

To provide when needed the opener password add that.

Beware paths and passwords with spaces certainly on windows need "double quotes"

qpdf --decrypt --password="blah blah" "my folder\in.pdf" "my folder\out.pdf"

Answer 5

The best solution I have found so far in these years since my original question is PDFUnlock. Feel free to present other solutions. Thanks.

Answer 6

There is a piece of software called PDF reDirect that allows you to create PDF documents from just about any program that can print. The software installs a printer called "PDF reDirect" on your computer and when you want to use the software you print the document to that printer. Perhaps you can print the document to that software and then you can resave it after that without the DRM.

I have never tried this before, just a thought.

Answer 7

The Problem with a re-printing the document to PDF is that the protected document may be printing restricted. So I guess the PDF printer route would work only for documents that aren't print protected already.

Answer 8

Assuming the document isn't protected against printing (in which case the print-and-scan method wouldn't work either), you can use any of the pdf converter programs that work by pretending to be a printer.

The two I've used are
  CutePDF: http://www.cutepdf.com/
  PDFCreator: http://en.pdfforge.org/pdfcreator

Of those, I prefer CutePDF - it's much faster.

Answer 9

Sorry to take the Accepted Answer checkmark away from ya, but I found the best solution in this eHow article. I downloaded the FreewarePDFUnlocker.msi file it mentions (I did check for viruses, everything was good), followed the simple instructions, and it worked perfectly.

Answer 10

Online unlocker that worked for me is FoxyUtils Unlock PDF which

• is free and does not require registering;
• has a drag & drop browser interface;
• accepts multiple files;
• maximum file size for upload is 50 MB;
• there is no time limit as with other sites (e.g. only 2 files per hour);
• limited to files with PDF encryption as defined in the PDF standard; files with encryption such as a DRM, are not handled;
• can also convert (to/from DOC, JPG), merge, split, compress, protect PDF files;
• resulting files are actually smaller than the originals (i.e. it does not add 10-20% overhead as other sites);
• there doesn't seem to be any quality decrease in the result;
• files are removed after completion or within an hour of inactivity (at least they claim).

Answer 11

Tiny Windows apps that can be used:

• PDFill PDF Tools
• SheelApps PDFTools

They don't have explicit option to unlock PDFs, but you can do fake operations, like reverse pages and then reverse once again, or merge PDF with an empty-page PDF, to achieve effectively the same.