Mass File Migrate supports file migration amongst Production (prod) orgs, amongst Sandbox orgs, and between Production (prod) and Sandbox orgs in Salesforce.
PS: View Mass File Migrate Salesforce file migration app on Salesforce AppExchange:
https://appexchange.salesforce.com/appxListingDetail?listingId=e9874a66-2001-4e3d-8a29-3a2ed7f584c4