How do I rename a local Git branch?

tl;dr

Here's how to rename a local Git branch:

First, you need to rename the current branch:

git branch -m <newname>

The -m flag is short for --move.

If you want to rename a branch while pointing to any branch, use the following command:

git branch -m <oldname> <newname>

Once you have renamed the branch, you need to push the new name to the remote branch and reset the upstream branch:

git push origin -u <newname>

Finally, you need to delete the old remote branch:

git push origin --delete <oldname>

If you are using Windows or another case-insensitive filesystem, use -M if there are only capitalization changes in the name. Otherwise, Git will throw a "branch already exists" error.

git branch -M <newname>

You can also create an alias for git rename:

git config --global alias.rename 'branch -m'