diffr

diffr enhances unified diff output by computing word-level changes within each hunk using Myers' longest common subsequence algorithm. Rather than highlighting entire changed lines, it identifies precise insertions and deletions at the token level and displays them with customizable colors, making it much easier to see exactly what changed.

The tool follows Unix philosophy: it reads a diff from stdin and writes enhanced output to stdout, making it compatible with any diff pipeline. It integrates naturally with Git by configuring it as a pager and diff filter in .gitconfig.

Basic usage

# Pipe git diff output through diffr.
git diff | diffr

# View a specific commit with word-level highlighting.
git show HEAD | diffr

# Add line numbers to the output.
git diff | diffr --line-numbers

gitconfig setup

[core]
    pager = diffr

[interactive]
    diffFilter = diffr

Custom colors

# Customize highlight colors for removed and added tokens.
git diff | diffr --colors refine-removed:background:200,0,0:foreground:white:bold \
                 --colors refine-added:background:0,150,0:foreground:white:bold