Spanner migration tool review
A focused, self-hosted tool for assessing and migrating relational databases to Cloud Spanner.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Spanner migration tool (SMT) is an open-source migration tool from Google Cloud for database administrators and developers moving relational databases to Cloud Spanner. Its stated workflows cover assessment, schema conversion, and data migration, making it a focused option for teams targeting that destination rather than a general-purpose database migration product. It is available for self-hosted deployment and is positioned for small, mid-market, and enterprise teams; the listed integration is Google Cloud Spanner.
The main appeal is the combination of assessment and migration steps in one open-source tool. Schema conversion addresses a specific part of moving relational databases to Spanner, while the data migration workflow handles transferring data. Teams can run SMT as part of their own migration process. The product description does not detail migration modes, source-specific support, or how its assessment evaluates a database, so organizations with varied source systems or complex conversion requirements should check whether the available workflows fit their needs before adopting it.
SMT itself is open source, but that does not make a broader migration cost-free: Google Cloud services used alongside the tool may incur separate charges. Choose it when Cloud Spanner is the target and a self-hosted, open-source workflow for assessment, schema conversion, and data migration suits the team. It is less suitable for organizations seeking a tool spanning multiple destinations or a more fully specified set of migration methods; those needs call for evaluating alternatives against their source and destination requirements.
Spanner migration tool pros and cons
- Where it wins
- Includes migration assessment and schema conversion workflows.
- Supports data migration from relational database sources.
- Open source and available for self-hosted deployment.
- Where it doesn't
- Focused on migration to Google Cloud Spanner.
- Requires users to run the tool as part of their migration process.
- Google Cloud services used alongside it may incur separate charges.
Spanner migration tool fact sheet, pricing and score →
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