diff-so-fancy 
diff-so-fancy strives to make your diffs human readable instead of machine readable. This helps improve code quality and helps you spot defects faster.
Screenshot
Vanilla git diff vs git and diff-so-fancy
Install
Installation is as simple as downloading the diff-so-fancy script to a directory in your path.
Windows users may need to install MinGW or the Windows subsystem for Linux.
diff-so-fancy is also available from NPM, Nix, brew, and as a package on Arch Linux.
Usage
Configure git to use diff-so-fancy for all diff output:
git config --global core.pager "diff-so-fancy, less --tabs=4 -RFX"
Improved colors for the highlighted bits
The default Git colors are not optimal. The colors used for the screenshot above were:
git config --global color.ui true
git config --global color.diff-highlight.oldNormal "red bold"
git config --global color.diff-highlight.oldHighlight "red bold 52"
git config --global color.diff-highlight.newNormal "green bold"
git config --global color.diff-highlight.newHighlight "green bold 22"
git config --global color.diff.meta "11"
git config --global color.diff.frag "magenta bold"
git config --global color.diff.commit "yellow bold"
git config --global color.diff.old "red bold"
git config --global color.diff.new "green bold"
git config --global color.diff.whitespace "red reverse"
Options
markEmptyLines
Should the first block of an empty line be colored. (Default: true)
git config --bool --global diff-so-fancy.markEmptyLines false
changeHunkIndicators
Simplify git header chunks to a more human readable format. (Default: true)
git config --bool --global diff-so-fancy.changeHunkIndicators false
stripLeadingSymbols
Should the pesky + or - at line-start be removed. (Default: true)
git config --bool --global diff-so-fancy.stripLeadingSymbols false
useUnicodeRuler
By default, the separator for the file header uses Unicode line-drawing characters. If this is causing output errors on your terminal, set this to false to use ASCII characters instead. (Default: true)
git config --bool --global diff-so-fancy.useUnicodeRuler false
rulerWidth
By default, the separator for the file header spans the full width of the terminal. Use this setting to set the width of the file header manually.
git config --global diff-so-fancy.rulerWidth 47 # git log's commit header width
Contributing
Pull requests are quite welcome, and should target the next branch. We are also looking for any feedback or ideas on how to make diff-so-fancy even fancier.
Other documentation
License
MIT