Rename master branch on GitHub

gistfile1.sh

git branch -m master newname
git push origin newname
# Change "Default Branch" in settings/options in GitHub
git push origin :master

Suggestion:

prefix this with

git checkout master
git pull origin master  # git reset --hard origin/master perhaps too aggressive

just in case you're doing this in batch right now and maybe forgot to check which branch you had checked out locally before executing.

(I know this gist is from 6 years ago but it was the top Google hit when I searched for "rename master branch github")

Without git push -u / --set-upstream your local newname branch would keep tracking origin/master, which you
end up deleting.

# Rename master branch to newname
git branch -m master newname
# Push newname branch to origin and track origin/newname instead of origin/master
git push -u origin newname
# Change "Default branch" in Settings / Branches in Github
# Delete origin/master
git push origin :master