git prune local branches

git fetch origin --prune

# for pruning of local branches that have been deleted on remote
git remote prune origin

# for checking local branches and if they can be deleted
# because they have been merged into another branch already
git branch --merged >/tmp/merged-branches && \
  vi /tmp/merged-branches && xargs git branch -d </tmp/merged-branches

git branch --merged master | grep -v '^[ *]*master$' | xargs git branch -d

npx git-removed-branches --prune