1. If the document library has classic view and you want to switch to modern experience, navigate to the library and select Library Settings from the Ribbon.
2. If the document library has modern view and you want to switch to classic experience, navigate to the library and click Settings Icon from top right and click Library settings.
3. In the Library settings page, click Advanced settings under the General Settings section.
4. In the Advanced settings page, scroll down to List experience.
- Default experience set by my administrator – Choose this option if you want to set the library experience as the option set by SharePoint administrator.
- New experience – Choose this option to set the library experience to the modern experience.
- Classic experience – Choose this option to set the library experience to classic.
SharePoint Online administrators can also change the default experience for all document libraries from the admin center.
1. Navigate to SharePoint Online Admin Center.
2. Click settings from the left navigation.
3. On the settings page select either Classic experience or New experience from SharePoint Lists and Libraries experience options
4. Selected experience option will be applied to all libraries in the tenant.