Theme Duplicate: How to make a backup of your theme
Always make a duplicate of your theme before adding any code. This will save you if anything goes wrong or if you decide not to use the added code in the future. We can not support or be responsible of any code changes that you make to your theme. For that reason, save yourself and make a duplicate first.
Make a duplicate before any code changes. From the Actions link of your live or draft theme, choose Duplicate:
Once you have a duplicate copy, you can keep that as your safe theme to rollback to in case there's any issue with your changes or you can modify the duplicate theme without affecting your live theme. If the duplicate theme changes are good, then you can publish it to become your live theme.