SharePoint Migration Assessment Tool-SMAT:
“SharePoint Migration Assessment Tool” or SMAT for short. The tool is a simple command line executable that scans the contents of a SharePoint farm to help identify the impact of migrating to SharePoint Online with Office 365.
The SMAT tool is available in two modes: Assessment and Identity Mapping. The assessment mode runs scans against the SharePoint farm and associated content looking for issues that have been known to cause problems for customers migrating into SharePoint Online. The Identity Mapping mode allows you to generate a report of all the user and group identities that have access to your SharePoint environment and attempts to map those identities to Azure AD user and group identities
The current version of SMAT supports checking the following items: