Open http://winmerge.org.
Click Download Now to download application.
Run installation file.
You can install application with default settings.
The application will automatically start when the installation is done.
Click Open icon above.
Select files you want to compare.
On the left side you will see review of the whole file, where changes are marked with different colors.
Click one of the changes.
In my case you can see, that the specific part of the second file was erased.
This also applies if the text was added to the file. The changes will be seen on the right side.
This is the way how we can really quickly find difference between two files.
Also recommended:
Web editing the PDF document
