How can I visualize per-character differences in a unified diff file?

Question

Say I get a patch created with git format-patch. The file is basically a unified diff with some metadata. If I open the file in Vim, I can see which lines have

Answer 1

Here are some versions with less noisy output than git diff --word-diff-regex=<re> and that require less typing than, but are equivalent to, git diff --color-words --word-diff-regex=<re>.

Simple (does highlight space changes):

git diff --color-words

Simple (highlights individual character changes; does not highlight space changes):

git diff --color-words=.

More complex (does highlight space changes):

git diff --color-words='[^[:space:]]|([[:alnum:]]|UTF_8_GUARD)+'

In general:

git diff --color-words=<re>

where <re> is a regexp defining "words" for the purpose of identifying changes.

These are less noisy in that they color the changed "words", whereas using just --word-diff-regex=<re> surrounds matched "words" with colored -/+ markers.