In this article, you will learn how to change the default experience of all the lists and libraries in SharePoint 2013 Online.
Introduction In SharePoint 2013 Online, Microsoft has changed the look and navigation for SharePoint Lists and Libraries. As an administrator, you can switch the user experience (Classic/New Experience) for all the list and libraries. In this article, you will learn how to change the default UX for all the lists and libraries. Change the default Experience
Summary: Thus, in this article, you saw how to change the default experience for all the lists and libraries in SharePoint 2013 Online.
SharePoint Online And Office 365 Administration