Pet-projects are useful to explore new technologies, to experiment with new features and approaches, and to get down the basics before diving into more advanced projects.

It might be a simple app or anything else with no serious use. Based on your learning path, you might do lots of them and your workspace can get a mess pretty quickly. So how do you organize them?

Do you develop them locally and then delete them or maybe leave them hoping you will add features later on when re-visiting?

Do you prefer to use some online sandboxes like Codepen or CodeSandBox instead, cause of easy set-up, access and no local mess?

Maybe you create a GitHub repo for each for version control/branches for experimenting and clone options later if you delete the local repo?

Or maybe you try to develop them into something useful, host them on Netlify (or services like Heroku for backend) and add them to your portfolio?