In today's post, we will look at how to migrate a SharePoint site and its contents from an on-premises environment to SharePoint Online.
To perform this transition, we will need the SharePoint Migration Tool (SPMT). We will open the SPMT and alternately enter the credentials and details for both the Online and On-premises environments.
Step-by-Step Migration Process
From the program, select "Add new migration" under the "SharePoint Migration in Progress" section.

Next, select "Single source URL".

Then, choose "Site migration".

Enter the URL for the on-premises environment hosting the site. Select "Only this site" if you want just that specific site. If you want to include sub-sites, select "This site and all subsites".

Next, select "SharePoint".

Enter the destination URL where you want the site to be moved in the Online environment.

You will then need to provide a name for the Migration link.

Configuring Settings
Following this is the "Review Settings" screen, where you can use toggles to choose which settings should be active.

For additional configurations, select "View all settings". This allows you to enable more advanced options.

You will see a series of options, such as:
Preserving versioning.
Maintaining permissions (if users map correctly from On-prem to Online).
Migrating files starting from a specific date.
Migrating metadata and content types.


Important Note
It is worth noting that you may often encounter various errors during the migration. These are usually related to how the on-premises SharePoint was structured—for example, if you have used custom columns, managed metadata, or implemented custom solutions using 3rd-party tools.