I'm sure many know, but for those who don't, `diff` (and `git diff`) accept -w and -b to ignore all white space and changes in the amount of white space, respectively. I find these very handy.

Somewhat related, if you're looking at a diff on GitHub and want to ignore whitespace, you can just tack on `?w=1` to the URL (https://github.com/blog/967-github-secrets).