Migrating from SharePoint On-Premises to Microsoft 365 with Microsoft MVP Daniel Glenn

[@prasadvihaan2023]

How to migrate sharepoint 2013 subsites to sharepoint online

[@nickmastera]

Try by using the Microsoft migration tool and 3rd party tool, migrate them as sites and organize them in Hub sites. Avoid sub sites in SPO

[@VladTalksTech]

I would agree - either Microsoft Migration tool or a 3rd party tool like Sharegate!