Question 1

Does it catch invisible differences?

Accepted Answer

The comparison is character-level, so invisible differences such as trailing spaces or different line endings show up too — and those are often the ones causing the actual bug.

Question 2

Why use this instead of git diff?

Accepted Answer

When what you're comparing isn't in version control: two API responses on your clipboard, logs from two servers, or two versions of text from an email.

Text Diff