Steps to clear out the history of a git/github repository

git-clearHistory

-- Remove the history from 
rm -rf .git

-- recreate the repos from the current content only
git init
git add .
git commit -m "Initial commit"

-- push to the github remote repos ensuring you overwrite history
git remote add origin git@github.com:<YOUR ACCOUNT>/<YOUR REPOS>.git
git push -u --force origin master

Works fine for me. I had a customer who never finished paying me for work, so nuked the code in the remote repo and added my ransom to the README.

...
git push --mirror --force

Thank you, @heshanlk.

Adding a variable to capture the default branch name (it might be master or main):

#!/bin/bash

default_branch=`basename $(git symbolic-ref --short refs/remotes/origin/HEAD)`

git checkout --orphan tmp
git add -A				# Add all files and commit them
git commit
git branch -D $default_branch		# Deletes the default branch
git branch -m $default_branch		# Rename the current branch to default
git push -f origin $default_branch	# Force push default branch to github
git gc --aggressive --prune=all		# remove the old files

Thanks.

❤️

Save yourself a world of pain and use main as default branch... blame Github monopoly for causing this chaos.
In git 2.23 / replit's default / NixOS 22_05 default, use the following, as it has no concept of default branch:

git branch main
git checkout main
git branch -d master

Using just a branch isnt a good concept for branching.

Its always depends about how your workflow looks like and then learn how to branch.

Best regards

worked like charm

Is it possible to delete the history from within Github? Thanks.

Yes. You need to contact GitHub support and they can run gc on the GitHub repo. Everything that is not reachable from a branch or tag will get cleaned up.

The instructions above are all around creating new branches that don't connect to the old history. So the old history will be eligible for gc (garbage collection). Keep in mind that aside from branches and tags, PRs and Issues might have links to old history and so they will prevent gc.