How to compare the differences between two PDF files on Windows?

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

A couple of the comments below suggest they don't see any difference. That means the plug-in isn't installed correctly. Here's how:

Put the files where the xdocdiff plugin's readme file says to put them (there are two places; I won't list them here as filenames can change, etc. — read the readme)
In WinMerge, go to Plugins > List and tick the ""Enable Plugins"" checkbox (this step is missing from the xdocdiff readme)
In WinMerge, choose Plugins > Automatic Unpacking (this was disabled prior to step 2)

Then when comparing, you'll see what look like text files in the comparison windows."

"I recently found this and I love it.

github.com/vslavik/diff-pdf

Cross platform, free, and works well.

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}"

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

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

Not free, but there is a thirty day trial."

"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."