How to compare a local Git branch with its remote branch

Question

How can I see the diff between a local branch and a remote branch?

Answer 1

git diff <local branch> <remote>/<remote branch> 

For example, git diff main origin/main, or git diff featureA origin/next

Of course to have said remote-tracking branch you need to git fetch first; and you need it to have up-to-date information about branches in the remote repository.

Answer 2

To update remote-tracking branches, you need to type git fetch first and then:

git diff <mainbranch_path> <remotebranch_path> 

You can git branch -a to list all branches (local and remote) and then choose the branch name from the list (just remove remotes/ from the remote branch name.

Example: git diff main origin/main (where "main" is the local main branch and "origin/main" is a remote, namely the origin and main branch.)