Amazon EventBridge vs SNS

Amazon EventBridge and SNS are both AWS pub/sub services, but EventBridge is the evolution of SNS for event-driven architectures. EventBridge adds content-based routing, schema discovery, SaaS integration, and event replay — capabilities SNS lacks.

Routing Power

SNS filters on message attributes — key-value metadata attached to messages. Filters can match exact values, prefixes, or numeric ranges. This works for simple routing but cannot inspect the message body.

EventBridge routes on the full event payload. Rules can match any field at any depth in a JSON event. You can route based on detail.orderStatus, source, or complex nested conditions. This content-based routing is dramatically more flexible.

AWS Service Integration

EventBridge is the native event bus for AWS. When an EC2 instance changes state, an S3 object is created, or a CodeDeploy deployment succeeds, EventBridge receives the event automatically. SNS does not receive these events — you must configure CloudWatch Events or custom publishing.

Event Archive and Replay

EventBridge can archive all events matching a pattern and replay them later. This is invaluable for debugging, testing, and recovery. SNS has no storage — once a message is delivered, it is gone.

When SNS Still Wins

SNS handles higher throughput more naturally and is cheaper per message. For simple fan-out at high volume — broadcasting notifications to millions of endpoints — SNS is more cost-effective. SNS also supports unique subscriber types like email, SMS, and mobile push.

The Modern Pattern

New event-driven architectures on AWS should default to EventBridge for event routing and fall back to SNS only for notification-specific endpoints (email, SMS). See our system design interview guide for more on AWS messaging patterns.