How can I delete all Git branches which have been merged?
NOTE: You can add other branches to exclude like master and dev if your workflow has those as a possible ancestor. Usually I branch off of a "sprint-start" tag and master, dev and qa are not ancestors.
First, list locally-tracking branches that were merged in remote (consider using -r flag to list all remote-tracking branches).
git branch --merged
You might see few branches you don't want to remove. We can add few arguments to skip important branches that we don't want to delete like master or a develop. The following command will skip master branch and anything that has dev in it.
git branch --merged| egrep -v "(^\*|master|main|dev)"
If you want to skip, you can add it to the egrep command like the following. The branch skip_branch_name will not be deleted.
git branch --merged| egrep -v "(^\*|master|main|dev|skip_branch_name)"
To delete all local branches that are already merged into the currently checked out branch:
git branch --merged | egrep -v "(^\*|master|main|dev)" | xargs git branch -d
You can see that master and dev are excluded in case they are an ancestor.
You can delete a merged local branch with:
git branch -d branchname
If it's not merged, use:
git branch -D branchname
To delete it from the remote use:
git push --delete origin branchname
git push origin :branchname # for really old git
Once you delete the branch from the remote, you can prune to get rid of remote tracking branches with:
git remote prune origin
or prune individual remote tracking branches, as the other answer suggests, with:
git branch -dr branchname
To delete all branches on remote that are already merged:
git branch -r --merged | grep -v master | sed 's/origin\//:/' | xargs -n 1 git push origin
In more recent versions of Git
git branch -r --merged | grep -v master | sed 's/origin\///' | xargs -n 1 git push --delete origin
UPDATE (by @oliver; since does not fit in comment, but enough answers already): if you are on branch ABC then ABC will appear in the results of git branch -r --merged because the branch is not specified, so branch defaults to current branch, and a branch always qualifies as merged to itself (because there are no differences between a branch and itself!).
So either specify the branch:
git branch -r --merged master | grep -v master ...
OR first checkout master:
git checkout master | git branch -r --merged | grep -v ...