AWS EventBridge is the backbone of event-driven architectures on AWS, routing events from your applications, SaaS partners, and AWS services to targets like Lambda, SQS, and Step Functions. The pricing model is straightforward for basic event routing but includes several components that can add up: Pipes, Scheduler, Schema Registry, and Archive/Replay.
TL;DR: Custom events cost $1.00 per million published to EventBridge. AWS service events and partner events are free. EventBridge Pipes costs $0.40 per million invocations for filtering and enrichment. Scheduler invocations are free. Archive and Replay costs $0.10/GB stored. For most architectures, EventBridge is cheaper than building equivalent routing with SNS and Lambda.
Event Bus Pricing
| Event Source | Cost |
|---|---|
| Custom Events | $1.00/million events |
| AWS Service Events | Free |
| SaaS Partner Events | Free |
| Cross-Account Events | $1.00/million (charged to sender) |
| Schema Discovery | Free |
What Counts as an Event?
Every PutEvents API call publishes one or more events, and each individual event in the batch counts toward billing. Events can be up to 256 KB in size. A single PutEvents call with 10 events counts as 10 events for billing purposes.
AWS service events (EC2 state changes, S3 object notifications, CodePipeline status updates) are delivered to the default event bus at no charge. This makes EventBridge an excellent free alternative to polling AWS APIs for state changes.
For a system publishing 50 million custom events per month:
| Component | Calculation | Monthly Cost |
|---|---|---|
| Custom Events | 50M x $1.00/M | $50.00 |
| AWS Events (100M) | Free | $0.00 |
| Total | $50.00 |
EventBridge Pipes Pricing
| Component | Price |
|---|---|
| Pipe Invocations | $0.40/million |
| Enrichment Compute | Standard Lambda/Step Functions rates |
How Pipes Work
EventBridge Pipes connect event sources (SQS, DynamoDB Streams, Kinesis, Kafka) to targets with optional filtering, enrichment, and transformation. Each time a pipe processes a batch of records, it counts as one invocation.
Pipes are cost-effective for point-to-point integrations. Connecting a DynamoDB Stream to a Lambda function via Pipes costs $0.40/million invocations for the pipe itself, compared to the alternative of publishing events to EventBridge at $1.00/million and then routing them.
EventBridge Scheduler Pricing
| Component | Price |
|---|---|
| Scheduler Invocations | Free |
| At-rest Schedules | Free |
EventBridge Scheduler lets you create one-time or recurring schedules that invoke any of over 270 AWS service targets. There is no charge for creating schedules or for invocations. You only pay for the target service (Lambda invocation, Step Functions execution, etc.). This makes Scheduler a free replacement for CloudWatch Events scheduled rules and cron-based Lambda triggers.
Archive and Replay Pricing
| Component | Price |
|---|---|
| Event Archive Storage | $0.10/GB-month |
| Event Replay | $0.10/GB replayed |
| Event Processing | Free (no per-event replay charge) |
When to Use Archive and Replay
Event archiving stores a copy of every matched event for later replay. This is useful for debugging, disaster recovery, and reprocessing events after deploying bug fixes. A system archiving 10 million events per month (averaging 1 KB each) stores about 10 GB at $1.00/month.
Replay costs apply when you re-publish archived events back to the event bus. The replayed events also incur standard custom event charges at $1.00/million. Plan replay windows carefully to avoid unexpected costs from reprocessing large archives.
EventBridge vs SNS vs SQS
| Factor | EventBridge | SNS | SQS |
|---|---|---|---|
| Per-event/message cost | $1.00/million | $0.50/million publishes | $0.40/million requests |
| Pattern matching | Advanced content filtering | Basic filtering | No filtering |
| Targets | 20+ AWS services directly | Lambda, SQS, HTTP, email | Single consumer |
| Schema Registry | Built-in (free) | Not available | Not available |
| Event replay | Built-in ($0.10/GB) | Not available | DLQ only |
| Best for | Event routing, fan-out | Simple pub/sub, notifications | Task queues, decoupling |
EventBridge costs 2x more per event than SNS ($1.00 vs $0.50/million) but provides content-based filtering, schema discovery, and direct integrations that eliminate Lambda glue functions. For architectures that would need SNS plus Lambda for filtering and routing, EventBridge is often cheaper overall.
Cost Optimization Strategies
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Leverage free AWS service events. Route EC2, S3, CodePipeline, and other AWS service events through EventBridge at zero cost instead of building custom polling or notification mechanisms.
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Use Pipes instead of EventBridge for point-to-point. When connecting a single source to a single target (DynamoDB Stream to Lambda), Pipes at $0.40/million is 60% cheaper than publishing custom events at $1.00/million.
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Filter events at the source. Apply event patterns to reduce the number of events that trigger downstream processing. Filtering is free and reduces costs for Lambda, Step Functions, and other targets.
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Replace CloudWatch Events rules with Scheduler. EventBridge Scheduler is free for invocations, while CloudWatch Events rules that trigger periodic Lambda functions still incur custom event charges.
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Set archive retention policies. Configure maximum retention periods for event archives to prevent unbounded storage growth. A 30-day retention policy keeps archive costs predictable.
-
Batch events when possible. The
PutEventsAPI accepts up to 10 events per call, reducing API call overhead. While each event is still billed individually, batching reduces network overhead and improves throughput.
Related Guides
- AWS SQS Pricing: Standard vs FIFO Queue Costs
- AWS SNS Pricing Guide
- AWS Lambda Pricing Guide
- AWS Step Functions Pricing Guide
FAQ
Is EventBridge cheaper than SNS for event routing?
It depends on the architecture. EventBridge costs $1.00/million vs SNS at $0.50/million per event. However, EventBridge eliminates the need for Lambda functions to filter and route events, which can save $0.20-0.60/million in Lambda invocation costs. For complex routing with content-based filtering, EventBridge is typically cheaper overall.
Does EventBridge have a free tier?
EventBridge does not have a separate free tier, but AWS service events and partner events are always free. Scheduler invocations are also free. Only custom events published by your applications incur the $1.00/million charge.
How does EventBridge Scheduler compare to cron jobs?
EventBridge Scheduler is a fully managed, serverless scheduler that supports one-time and recurring schedules with no invocation charges. It replaces traditional cron jobs on EC2 instances (which cost compute time) and CloudWatch Events rules. Scheduler supports timezone-aware scheduling, flexible time windows, and dead-letter queues for failed invocations.
Lower Your EventBridge Costs with Wring
Wring helps you access AWS credits and volume discounts to lower your EventBridge costs. Through group buying power, Wring negotiates better rates so you pay less per million events.
