How to compare the differences between two PDF files?

Question

Do you know a good Windows software to compare PDF files side-by-side and show the modifications between the two?

It would be great if you can post both free and not-free products.

Answer 1

Try WinMerge with the xdocdiff plugin. Both are completely free. No strings attached.

Answer 2

On Linux and Windows you can use diffpdf (which differs from diff-pdf mentioned in this thread).

On Ubuntu install using:

sudo apt-get install diffpdf

See further this UbuntuGeek page on comparing pds textually or visually.

Answer 3

I recently found this and I love it.

https://github.com/vslavik/diff-pdf

Cross platform, free, and works well.

Answer 4

We also needed to compare PDFs at our company and were not satisfied with any of the solutions we found, so we made our own and just released version 2.0 today (9/5): i-net PDFC. It's not free, but we do offer a 30-day trial.

It's written in Java, so it's cross-platform.

What makes it special is that it compares the content as opposed to only the text (or just converting the pdf to an image and comparing the image). It also has a nice visual comparison tool.

Answer 5

You can also use Adobe Acrobat X. Its has built in PDF comparison functionality under "View -> Compare Documents.

Answer 6

Great tool and easy to use : Compare-It v4 (from http://www.grigsoft.com/)

Compares many different kind of files. It has some built-in converters, including one for PDF files.

I've used it quite a few times with satisfying results.

Really should try this. Trial version allows comparison for unlimited time.

Answer 7

Free, Not the best but...

I open both documents up and have them split screen against each other.

Not the most practical solution, but it works!

I have not seen a good DIFF package for PDF files and whilst manual and annoying, my way works!

Answer 8

Commercial: You can use the original Adobe Acrobat Professional, for a whopping $449 :
Compare a revised PDF to an earlier version.

If you decide on Acrobat, the comments on this page are pertinent to its use.

Answer 9

If you are comparing text inside a pdf, then Beyond Compare does this.

Not free, but there is a thirty day trial.

Answer 10

Don't know it, but there is also comparePDF (not free, but a 30 day trial possible): http://www.compare-pdf.com/download.htm

Answer 11

PDiff for Mac (on the AppStore). Side-by-side display of two PDFs with marked diffs, second pane with side-by-side display of the extracted texts. Differences in layout, even due to page breaks and column breaks handled smoothly. Free demo at http://www.csci.de/en/pdiff

According to the developers there will also be a windows port, however aiming at business customers (”professional" edition).

Answer 12

Here is a screenshot of diff-pdf in action - note that the text is not different in the PDF, but only fonts (and correspondingly, layout settings):

The call to obtain that image was:

diff-pdf --view testA.pdf testB.pdf

 

... where testA.pdf/testB.pdf are obtained by compiling this simple Latex file with pdflatex (accordingly for each pdf, see comment):

\documentclass[12pt]{article}


                        % without mathpazo: testA.pdf
\usepackage{mathpazo} % with mathpazo: testB.pdf
\usepackage{lipsum}


\title{A brand new test}
\author{Testulio}

\begin{document}

\maketitle

\lipsum[1-3]

\end{document}

Answer 13

Another less than ideal solution:

1. Convert both PDFs to Microsoft Word documents using one of the websites that do this for free.
2. Use the document comparison functionality in Word.

Depending on how complex the formatting in the PDFs is and the kind of changes you're looking for, this might be OK.

Answer 14

Diff Doc - not free.

Answer 15

For a very primitive form of synchronized scrolling between two pdf files, you can use the following autohotkey script I wrote. It assumes you have two SumatraPDF windows open. Press right to go to the next page in both windows, press left for the previous page.

#IfWinActive ,SumatraPDF
Right::
orig := WinExist("A")
WinGet, outvar, List, SumatraPDF
win1 := outvar1
win2 := outvar2
WinActivate, ahk_id %win1%
sendinput {Right}
WinActivate, ahk_id %win2%
sendinput {Right}
WinActivate, ahk_id %orig%
return

Left::
orig := WinExist("A")
WinGet, outvar, List, SumatraPDF
win1 := outvar1
win2 := outvar2
WinActivate, ahk_id %win1%
sendinput {Left}
WinActivate, ahk_id %win2%
sendinput {Left}
WinActivate, ahk_id %orig%
return

Answer 16

I used this (non ideal, but for me sufficient) solution:

• Convert PDF to plain text (in my case with Adobe Reader, free app)
• Use opendiff (included with XCode, free) and see changes