The default experience for most document libraries and lists has changed. This new, modern experience is recommended for most lists and libraries. It is faster, has simpler navigation and allows you to accomplish many common tasks more easily. However, you may want to switch the default experience for everyone to the classic experience.
Note: The steps below change the default experience for everyone. To use the classic experience just for yourself, select Return to classic SharePoint in the bottom, left corner of the page. To exit, select Exit classic experience.
Change the experience for a list or document library
In the modern experience for a list or document library, choose Settings and then List settings or Library settings.
In the classic experience, you'll find Library Settings or List Settings on the ribbon.
Select Advanced settings and find the List experience towards the end of the list of settings.
Choose one of the three options and select OK to save.
Important: Even when New experience is selected, you might see the classic experience sometimes.
Change the experience for all lists and libraries on a site
You can activate the site collection feature SharePoint Lists and Libraries experience to set the classic experience as the default for an entire site. Read how to enable or disable site collection features for more information.
When both the site collection feature is active and the List expereince for a list or libary is set to New experience, the new experience will be used.