Here’s a quick way to update commit author email and display name for previous commits in a local project.
Two things worth mentioning before using this:
If you change your email, it might no longer count as contributions on your GitHub/GitLab profile. But as long as you keep the old email as a hidden email connected to your account, it should work.
Remember that rewriting history in shared projects is a bad idea. Especially when working in a collaborative environment with other people. But for old local projects that you want to upload to a public Git repository, this method could be useful to hide some personal information.
git filter-branch --commit-filter ' if [ "$GIT_AUTHOR_EMAIL" = "firstname.lastname@example.org" ]; then GIT_AUTHOR_NAME="Your Name"; GIT_AUTHOR_EMAIL="email@example.com"; git commit-tree "$@"; else git commit-tree "$@"; fi' HEAD