Active Directory Migration Tool (ADMT 3.2)
Microsoft
Free
Legacy Warm - seeded online, short cutover window
Agent
Mid estates
Ad
What it is good at
The only free tool that does real inter-forest migration with SID history and password export. Migrates users, groups, computers and service accounts, and re-ACLs member servers.
Where it falls down
Unchanged since 2012 R2 and effectively in maintenance. Requires a two-way trust, is one-directional (no ongoing coexistence), has no GUI for large waves, and there is no built-in rollback - you must plan restores. Expect scripting.
Capabilities
- SID history
- Password migration / sync
- Coexistence during migration
- Object-level rollback
Cost and licensing
- Cost category
- Free — No licence cost from the vendor.
- Indicative price
- No licence cost
- Licence model
- Free Microsoft download, covered by your existing Windows Server licensing.
- How to license it
- Download ADMT 3.2 from the Microsoft Download Center. Free. Note it has not been updated since Windows Server 2012 R2 - it installs on newer servers only with documented workarounds, and it needs a SQL Server (Express is fine) instance.
- Lifecycle
- Legacy
- Vendor page
- https://learn.microsoft.com/troubleshoot/windows-server/active-directory/admt-guide-migrating-restructuring-active-directory-domains
Pricing and licensing last reviewed 2026-09-18. Indicative only - confirm with the vendor.
Supported sources
- Any platform
Supported targets
- Any platform
Scenarios it covers
- Inter-forest migration (forest A to forest B)
- Intra-forest restructure (domain to domain, same forest)
- Multi-domain / multi-forest consolidation
- Divestiture / carve-out (split one directory into two)
- Domain / forest rename or restructure in place