How to compare two pdf files and find the difference in terms of percentage

you may need a third party dll or so, to read a PDF file in case it is what you wish to do, e.g.

http://ift.tt/19kKSFJ

http://ift.tt/1j2xIA6

If you just only want to compare file size, then you can user "FileInfo.Length" for this.

http://ift.tt/1bsSsQy

regards

joon