Clean Slate for Kids Online Act of 2018 This bill amends the Children's Online Privacy Protection Act of 1998 to require the operator of any website or online service directed to children: to provide notice on the website about how an individual over age 13, or the guardian of an individual over 13, can request the deletion of all personal information in the operator's possession collected when the individual was a child; to promptly delete, upon request, all personal information in the operator's possession that was collected from or about the individual when the individual was a child; and to provide written confirmation of deletion. "Delete" means to remove personal information such that the information is not maintained in retrievable form and cannot be retrieved in the normal course of business. The bill allows a limited exception to the deletion requirement if the personal information collected from or about a child is necessary to respond to judicial process or to provide information to law enforcement agencies.