Amazon Database Migration Service vs Spanner migration tool

Amazon Database Migration Service (AWS DMS) is a SaaS service for moving relational databases, data warehouses, NoSQL databases and other data stores to AWS or between cloud and on-premises environments. It handles one-time migrations and continuous replication, with support for both like-for-like and cross-engine moves. AWS says more than 20 databases and data warehouses can serve as source or target endpoints. DMS Schema Conversion assesses schemas and converts many code objects, including views, stored procedures and functions, while identifying work that needs manual conversion. DMS Serverless provisions and scales capacity according to transaction volume, billed hourly. Multi-AZ deployment uses redundant replication instances, and interrupted migrations can resume. API and AWS CLI support automation, while CloudTrail and CloudWatch Logs provide integrations. TLS, VPC deployment, PrivateLink and column masking are available. At least one endpoint must be Amazon RDS or EC2; on-premises-to-on-premises replication is unsupported. The AWS Free Tier offers free with credits.

Spanner migration tool has no write-up on Specifiction yet; its figures are above.