Amazon MQ vs SQS

Amazon MQ and SQS are both AWS messaging services, but they serve different migration stories. Amazon MQ is a managed broker for applications already using ActiveMQ or RabbitMQ protocols. SQS is AWS's cloud-native queue service.

When Amazon MQ Exists

Amazon MQ exists for one primary reason: lift-and-shift migration. If you run ActiveMQ or RabbitMQ on-premises and want to move to AWS without changing application code, Amazon MQ lets you do that. Your existing AMQP, MQTT, or STOMP clients connect to Amazon MQ with just a connection string change.

Architecture Differences

Amazon MQ runs a managed instance of ActiveMQ Classic, ActiveMQ Artemis, or RabbitMQ on dedicated EC2 instances. You choose the instance type, and your throughput is bounded by that instance's resources. High availability uses active-standby failover.

SQS is a distributed, serverless service with no visible instances. Throughput scales automatically. There is no instance to size, no failover to configure, and no storage to manage.

Cost Comparison

Amazon MQ charges for broker instance hours and storage — the broker runs 24/7 regardless of traffic. An mq.m5.large costs roughly $150/month before storage.

SQS charges per API request ($0.40 per million). For low-to-moderate traffic, SQS is dramatically cheaper. For extremely high traffic, the costs converge.

The Migration Decision

AWS's own guidance is clear: use SQS for new applications and Amazon MQ for migrating existing applications that need protocol compatibility. For system design interviews, choose SQS unless the scenario explicitly involves migrating legacy messaging systems. See also our concepts guide and pricing page.