How to compare two tags with git?

$ git diff tag1 tag2

or show log between them:

$ git log tag1..tag2

sometimes it may be convenient to see only the list of files that were changed:

$ git diff tag1 tag2 --stat

and then look at the differences for some particular file:

$ git diff tag1 tag2 -- some/file/name

A tag is only a reference to the latest commit 'on that tag', so that you are doing a diff on the commits between them.

(Make sure to do git pull --tags first)

Also, a good reference: https://git-scm.com/docs/git-diff

If source code is on Github, you can use their comparing tool: https://help.github.com/articles/comparing-commits-across-time/

For a side-by-side visual representation, I use git difftool with openDiff set to the default viewer.

Example usage:

git difftool tags/<FIRST TAG> tags/<SECOND TAG>

If you are only interested in a specific file, you can use:

git difftool tags/<FIRST TAG>:<FILE PATH> tags/<SECOND TAG>:<FILE PATH>

As a side-note, the tags/<TAG>s can be replaced with <BRANCH>es if you are interested in diffing branches.