How can I generate a diff for a single file between two branches in github

Question

I need to generate a diff for a single file that will show the differences between two versions, which are actually tags in github. I then want to send this diff to someone via

Answer 1

Here is my workaround when the following issue applies.

This comparison is big! We’re only showing the most recent 250 commits

Copy the raw view of the file that you want to compare to https://gist.github.com/. Use the two specific commit points that you want to compare. Start with the older commit.

https://gist.github.com/ has a nice side-by-side diff view when you click 'Revisions'.