#####[Approaches to user account migration](https://fusionauth.io/blog/2021/03/23/migration-types/)
Migrating user data is fraught with risk. Of course, migrating any data is tough, but user accounts are even harder because any issue with the transfer affects human beings. Whether employees, customers, or potential clients, humans tend to react negatively to applications being inaccessible.
There are a few different approaches to migrating user accounts.
– The big bang migration.
With a big bang migration, you are moving all your users at one time.
– Segment by segment migration.
The segment by segment migration is an alternative to the big bang, with some significant overlap. This approach is essentially a series of “little bang” migrations, where you use the same approach, just with smaller chunks of users.
– Slow migration.
This approach is the logical endpoint of segment by segment migration. What if you made each chunk of accounts to be migrated as small as possible. Well, you end up with each segment being a single user.
_Authored by_ **Dan Moore**. **FusionAuth.io**.