Delete multiple git branches at once

The other day I was working on a git repository that had thousands of feature and fix branches, one of the problems with this is that the task that executed Gitversion, an utility that calculates the app version by its git history was taking too long because of the large amount of branches. Because of that, I looked into how to delete thousands of branches at once, and in this post we will be doing just that.

Open a git bash terminal, go to the root folder of the repository you will be deleting the branches, and the run the following command to output a list of all remote branches:

git branch -va --sort=committerdate --format='%(color:yellow)%(refname:short)%(color:reset):%(color:green)%(committerdate:short)%(color:reset)' > list-of-all-git-branches.txt

This will generate a list-of-all-git-branches.txt file with branches names and dates of last commit pushed, sorted by ascending order, if you want to invert the order (from newest to oldest), use --sort=-committerdate instead of --sort=committerdate

From here you can filter the file to determine which branches you will end up deleting. You can use the sed command to do this.

With the following command you can generate a file named filtered-branches.txt which will have all branches whose last commit was pushed on March of 2022:

sed -n '/2022-03-..$/p' ./list-of-all-git-branches.txt > filtered-branches.txt

With the next command you can generate a file named filtered-branches.txt which will have all the branches except for those that the last commit has been pushed in August of 2022:

sed '/2022-08-..$/d' ./list-of-all-git-branches.txt > filtered-branches.txt

Before deleting the branches, check if the resulting file (filtered-branches.txt) doesn’t have any branch that you don’t want to accidentally delete. Also it is necessary to delete origin/ at the beginning of each line for those branches that you don’t have on your disk, you can easily remove that with any text editor (like Notepad++) using a _regex expression like ^origin/ (which means all ocurrences where origin/ is at the beginning of the line, thanks to the ^ character).

Another thing you can do is to filter certain type of branches, after deleting the origin/ part, you can further filter for example for all branches that start with /feature and generate a new file with the branches that you will delete (only feature branches):

cat filtered-branches.txt | grep "^feature/" > git-branches-to-delete.txt

Double check that the branches you are going to delete are the correct and there are not any critical branch:

cat git-branches-to-delete.txt | awk -F ":" '{ print $1 }'

Once you are sure that the branches in git-branches-to-delete.txt are the correct, use the following command to delete them:

cat git-branches-to-delete.txt | awk -F ":" '{ print $1 }' | xargs -t -I {} git push origin -d {}

Then delete the files list-all-of-git-branches.txt, filtered-branches.txt and git-branches-to-delete.txt that you have generated.