Understanding DynamoDB Data Transfer Costs
DynamoDB data transfer costs:
- Free: Data transfer IN to DynamoDB
- Free: Data transfer between DynamoDB and other AWS services in the same region
- Charged: Data transfer OUT to the internet
- Charged: Cross-region replication (Global Tables)
Eliminate NAT Gateway Costs with VPC Endpoints
If your application runs in a private subnet, accessing DynamoDB typically requires a NAT Gateway, which costs ~$0.045/GB plus $32.85/month per gateway.
Solution: Use VPC endpoint gateways for DynamoDB. They’re free and route traffic directly within the AWS network.
Benefits:
- Zero data transfer costs for DynamoDB traffic
- No NAT Gateway monthly charges
- Improved security (traffic never leaves AWS network)
- Lower latency
Learn more about VPC endpoints for DynamoDB
Optimize Global Tables
Only replicate to regions where you actually serve traffic. Each replica region adds:
- Storage costs (duplicate data)
- Replicated Write Capacity Units (rWCUs)
- Cross-region data transfer charges
Review your global table configuration and remove unused replicas.