Use DotNet Framework based DCon
.gitconfig
# .gitconfig file in your home directory
[diff "bindocconverter"]
textconv=bindocconverter
prompt = false
[alias]
docdiff = diff --word-diff=color --unified=1
.gitattributes
# .gitattributes file in root folder of your git project
*.docx diff=bindocconverter
*.docm diff=bindocconverter
*.doc diff=bindocconverter
*.dotx diff=bindocconverter
*.dotm diff=bindocconverter
*.dot diff=bindocconverter
*.rtf diff=bindocconverter
*.odt diff=bindocconverter
*.xlsx diff=bindocconverter
*.xlsm diff=bindocconverter
*.xlsb diff=bindocconverter
*.xls diff=bindocconverter
*.csv diff=bindocconverter
*.xltx diff=bindocconverter
*.xltm diff=bindocconverter
*.xlt diff=bindocconverter
*.ods diff=bindocconverter
*.pptx diff=bindocconverter
*.pptm diff=bindocconverter
*.ppt diff=bindocconverter
*.potx diff=bindocconverter
*.potm diff=bindocconverter
*.pot diff=bindocconverter
*.ppsx diff=bindocconverter
*.ppsm diff=bindocconverter
*.pps diff=bindocconverter
*.odp diff=bindocconverter
*.pdf diff=bindocconverter