Modernizing and Migrating Older Sites to SharePoint Online

• SharePoint Online has site design and customization features not available in older on-premises versions.
• While SharePoint Online will generally display sites with older design elements after migration, the pages will lack some features and technologies that could benefit users.
• Sites designed for older versions of SharePoint could encounter problems when migrating to SharePoint Online.
• Tools and guidance are available to migrate SharePoint sites, but not all sites can easily be ported.

Site user interface and customization features offered in SharePoint Server 2010 and 2013 have been replaced by newer technologies in SharePoint Online, potentially causing problems when migrating sites from on-premises to hosted SharePoint. There is often no one-to-one mapping between so-called classic and modern site designs, and SharePoint Online has deprecated and removed some older technologies that it previously supported. When planning a migration to SharePoint Online, organizations should be aware of how feature retirements might affect their SharePoint sites and understand the available tools that can assist in content migration.