8 Best Open Source Alternatives to PubNub

1.Apache Kafka

32.8kApache-2.0Java Self-host

Apache Kafka is an open source distributed event streaming platform used by thousands of companies for high-performance data pipelines, streaming analytics, data integration, and mission-critical applications. Producers write streams of events to topics and consumers read them, in real time or replayed later.

• Publish and subscribe to streams of events via topics
• Durable, replicated, partitioned event log storage
• Stateful stream processing with Kafka Streams
• Data integration through Kafka Connect connectors

2.ThingsBoard

21.9kApache-2.0Java Self-host

ThingsBoard is an IoT platform that takes devices from connection to insight. It provisions and monitors your hardware, ingests their telemetry, processes that data, and surfaces it on live dashboards, all in one place that scales from a prototype to a production fleet.

• Provision and manage devices, assets, customers, and relations
• Telemetry collection over MQTT, CoAP, HTTP, LwM2M, and SNMP
• Rule chains for transforming data and raising alarms
• Built-in, custom, and SCADA dashboards with widgets

3.NATS

20kApache-2.0Go Self-host

NATS is a high-performance messaging system for services, devices, and distributed systems. It connects cloud, on-premise, edge, and IoT environments through a single lightweight server that runs anywhere from a large cluster down to a Raspberry Pi.

• Publish/subscribe and request-reply messaging
• Load-balanced queue groups for scaling consumers
• JetStream persistence, streaming, and replay
• Key-value and object stores built on JetStream

4.Apache Pulsar

15.3kApache-2.0Java Self-host

Apache Pulsar is a distributed pub-sub messaging and streaming platform for moving event streams and queued messages at scale. Its flexible messaging model and client API serve applications that need topics, queues, or both from a single broker.

• Horizontally scalable with millions of topics
• Strong ordering and consistency guarantees
• Low-latency durable storage
• Topic and queue semantics

5.RabbitMQ

13.7kOtherJavaScript Self-host

RabbitMQ is an open source, multi-protocol messaging and streaming broker. Applications exchange messages through it over AMQP 1.0 and AMQP 0-9-1, MQTT, STOMP, and the RabbitMQ Stream Protocol, so producers and consumers can speak whichever protocol suits them.

• AMQP 1.0 and AMQP 0-9-1 messaging
• MQTT 3.1, 3.1.1, and 5.0 support
• STOMP 1.0 through 1.2 support
• RabbitMQ Stream Protocol support

6.Eclipse Mosquitto

11kOtherC Self-host

Eclipse Mosquitto is a lightweight MQTT broker implementing protocol versions 5.0, 3.1.1, and 3.1. It moves messages between clients with a publish/subscribe model, and ships command-line utilities for testing and administration. Its small footprint suits everything from full servers down to low-power and embedded devices.

• MQTT broker for 5.0, 3.1.1, and 3.1
• C and C++ client library
• Publish and subscribe tools: mosquitto_pub, mosquitto_rr, mosquitto_sub
• Admin tools: mosquitto_ctrl, mosquitto_signal, mosquitto_passwd

7.Magistrala

2.6kApache-2.0Go Self-host

Magistrala is an IoT platform framework that gives engineers a single control plane for devices, users, and data. Rather than stitching together a broker, an auth layer, and a rule engine, you get a coherent system with one consistent model for identity, messaging, and observability.

• Native MQTT, HTTP, WebSocket, and CoAP connectivity
• Device provisioning and channel-based message control
• ABAC and RBAC with multi-tenant domains and access tokens
• Rules engine with alarms, triggers, and scheduled actions

8.Apache ActiveMQ

2.4kApache-2.0Java Self-host

Apache ActiveMQ is a high-performance message broker for moving messages reliably between applications and services. It speaks Jakarta Messaging 3.1.0, JMS 2.0, JMS 1.1, AMQP, MQTT, and HTTP/WS, so clients written for different stacks can all connect to the same broker.

• Jakarta Messaging 3.1.0, JMS 2.0, and JMS 1.1 support
• AMQP, MQTT, and HTTP/WS protocol support
• Network of brokers for distributing load
• Scheduled and delayed message delivery