Azure Event Grid quotas and limits

This article lists quotas and limits in Azure Event Grid.

Note

The following limits listed in this article are per region.

Event Grid throttle limits

Event Grid offers a standard tier and basic tier. Event Grid standard tier enables pub-sub using Message Queuing Telemetry Transport (MQTT) broker functionality and pull-delivery of messages through the Event Grid namespace. Event Grid basic tier enables push delivery using Event Grid custom topics, Event Grid system topics, Event domains, and Event Grid partner topics. See Choose the right Event Grid tier. This article describes the quota and limits for both tiers.

Event Grid Namespace resource limits

Azure Event Grid namespaces is available in public preview and enables MQTT messaging, and HTTP pull delivery. The following limits apply to namespace resources in Azure Event Grid.

Limit description	Limit
Event Grid namespaces per Azure subscription	50
Maximum throughput units per Event Grid namespace	40
IP Firewall rules per Event Grid namespace	16

MQTT limits in Event Grid namespace

The following limits apply to MQTT in Azure Event Grid namespace resource.

Note

Throughput units (TUs) define the ingress and egress event rate capacity in namespaces. They allow you to control the capacity of your namespace resource for message ingress and egress.

Limit description	Limit
MQTT sessions per Event Grid namespace	10,000 per throughput unit (TU)
Sessions per Event Grid namespace	10,000 per TU
Session Expiry Interval	8 hours, configurable on the Event Grid namespace
Inbound MQTT publishing requests per Event Grid namespace	1,000 messages per second per TU
Inbound MQTT bandwidth per Event Grid namespace	1 MB per second per TU
Inbound MQTT publishing requests per session	100 messages per second
Inbound MQTT bandwidth per session	1 MB per second
Outbound MQTT publishing requests per Event Grid namespace	1,000 messages per second per TU
Outbound MQTT bandwidth per Event Grid namespace	1 MB per second per TU
Outbound MQTT publishing requests per session	100 messages per second
Outbound MQTT bandwidth per session	1 MB per second
Max message size	512 KB
Segments per topic/ topic filter	8
Topic size	256 B
MQTTv5 response topic	256 B
MQTTv5 topic aliases	10 per session
MQTTv5 total size of all user properties	32 KB
MQTTv5 content type size	256 B
MQTTv5 correlation data size	256 B
Connect requests	200 requests per second per TU
MQTTv5 authentication data size	8 KB
Maximum keep-alive interval	1160
Topic filters per MQTT SUBSCRIBE packet	10
Subscribe and unsubscribe requests per Event Grid namespace	200 requests per second
Subscribe and unsubscribe requests per session	5 requests per second
Subscriptions per MQTT session	50
Subscriptions per Event Grid namespace	1 million
Subscriptions per MQTT topic	Unlimited, as long as they don't exceed the limit for subscriptions per Event Grid namespace or session
Registered client resources	10,000 clients per TU
CA certificates	10
Client groups	10
Topic spaces	10
Topic templates	10 per topic space
Permission bindings	100

Events limits in Event Grid namespace

The following limits apply to events in Azure Event Grid namespace resource.

Limit description	Limit
Event Grid namespace topics	100 per TU
Event ingress	1,000 events per second or 1 MB per second per TU (whichever comes first)
Event egress (push and pull APIs)	Up to 2,000 events per second or 2 MB per second per TU
Event egress (acknowledge, release, reject, and renew lock APIs)	Up to 2,000 events per second or 2 MB per second per TU
Maximum event retention on Event Grid namespace topics	7 days
Subscriptions per topic	500
Maximum event size	1 MB
Batch size	1 MB
Events per request	1,000

Custom topic, system topic, and partner topic resource limits

The following limits apply to Azure Event Grid custom topic, system topic, and partner topic resources.

Limit description	Limit
Custom topics per Azure subscription	100 When the limit is reached, you can consider a different region or consider using domains, which can support 100,000 topics.
Event subscriptions per topic	500 This limit can’t be increased.
Publish rate for a custom or a partner topic (ingress)	5,000 events of 64 KB size per second or 5 MB per second (whichever comes first). An event is counted for limits and pricing purposes as a 64KB data chunk. So, if the event is 128 KB, it counts as two events.
Event size	1 MB This limit can’t be increased.
Maximum event retention on topics	1 day. This limit can't be increased.
Number of incoming events per batch	5,000 This limit can’t be increased
Private endpoint connections per topic	64 This limit can’t be increased
IP Firewall rules per topic	128

Domain resource limits

The following limits apply to Azure Event Grid domain resource.

Limit description	Limit
Domains per Azure subscription	100
Topics per domain	100,000
Event subscriptions per topic within a domain	500 This limit can’t be increased
Domain scope event subscriptions	50 This limit can’t be increased
Publish rate for a domain (ingress)	5,000 events of 64 KB size per second or 5 MB per second (whichever comes first). An event is counted for limits and pricing purposes as a 64KB data chunk. So, if the event is 128 KB, it counts as two events.
Maximum event retention on domain topics	1 day. This limit can't be increased.
Private endpoint connections per domain	64
IP Firewall rules per topic	128

Next steps

See Azure subscription and service limits, quotas, and constraints for quotas and limits of all Azure services.