Best Free Event Brokers of 2025

HiveMQ is the most trusted enterprise MQTT platform, purpose-built to connect anything via MQTT, communicate reliably, and control IoT data. The platform can be deployed anywhere, on-premise or in the cloud, giving developers the flexibility and freedom they need to evolve as their IoT deployment grows. HiveMQ is reliable under real-world stress, scales without limits, and provides enterprise-grade security to meet the needs of organizations at any stage of digital transformation. The extensible platform provides seamless connectivity to the leading data streaming, databases, and data analytics platforms, plus offers a custom SDK for a perfect fit in any stack.

RabbitMQ is a lightweight solution that can be effortlessly deployed both on-premises and in cloud environments. It is compatible with various messaging protocols, making it versatile for different use cases. Furthermore, RabbitMQ can be configured in distributed and federated setups, which cater to demanding scalability and high availability needs. With a vast user base, it stands out as one of the leading open-source message brokers available today. Organizations ranging from T-Mobile to Runtastic leverage RabbitMQ, showcasing its adaptability for both startups and large enterprises. Additionally, RabbitMQ is compatible with numerous operating systems and cloud platforms, offering a comprehensive suite of development tools for popular programming languages. Users can deploy RabbitMQ using tools like Kubernetes, BOSH, Chef, Docker, and Puppet, facilitating seamless integration into their existing workflows. Developers can also create cross-language messaging solutions using their preferred programming languages, such as Java, .NET, PHP, Python, JavaScript, Ruby, and Go, enhancing its utility across various projects.

A managed service facilitates two-way communication between IoT devices and Azure, ensuring that your Internet of Things (IoT) application maintains secure and dependable connections with the devices it oversees. Azure IoT Hub acts as a cloud-based backend, capable of linking nearly any device seamlessly. Enhance your solution by integrating from the cloud to the edge, utilizing per-device authentication, built-in device management, and scalable provisioning options. By leveraging device-to-cloud telemetry data, you can monitor the status of your devices and easily create message routes to various Azure services without the need for coding. Additionally, cloud-to-device messaging allows for the reliable transmission of commands and notifications to your connected devices, with the ability to track delivery through acknowledgment receipts. In the event of connectivity issues, the system automatically resends messages to ensure communication continuity. With Azure IoT Central, we aim to go beyond mere proof of concept by assisting you in developing advanced, industry-leading solutions using a fully managed IoT application platform that streamlines innovation. This comprehensive approach empowers organizations to fully harness the potential of IoT technology in their operations.

One Platform for Realtime Communication: A platform to build and operate real-time interactivity for web, mobile, AI/ML, IoT, and Edge computing applications Faster & Easier Deployments: SDK support for 50+ mobile, web, server, and IoT environments (PubNub & community supported) and more than 65 pre-built integrations with external and third-party APIs to give you the features you need regardless of programming language or tech stack. Scalability: The industry’s most scalable platform capable of supporting millions of concurrent users for rapid growth with low latency, high uptime, and without financial penalties.

Ably is the definitive realtime experience platform. We power more WebSocket connections than any other pub/sub platform, serving over a billion devices monthly. Businesses trust us with their critical applications like chat, notifications and broadcast - reliably, securely and at serious scale.

Solace is a specialist in Event-Driven-Architecture (EDA), with two decades of experience providing enterprises with highly reliable, robust and scalable data movement technology based on the publish & subscribe (pub/sub) pattern. Solace technology enables the real-time data flow behind many of the conveniences you take for granted every day such as immediate loyalty rewards from your credit card, the weather data delivered to your mobile phone, real-time airplane movements on the ground and in the air, and timely inventory updates to some of your favourite department stores and grocery chains, not to mention that Solace technology also powers many of the world's leading stock exchanges and betting houses. Aside from rock solid technology, stellar customer support is one of the biggest reasons customers select Solace, and stick with them.

StreamNative transforms the landscape of streaming infrastructure by combining Kafka, MQ, and various other protocols into one cohesive platform, which offers unmatched flexibility and efficiency tailored for contemporary data processing requirements. This integrated solution caters to the varied demands of streaming and messaging within microservices architectures. By delivering a holistic and intelligent approach to both messaging and streaming, StreamNative equips organizations with the tools to effectively manage the challenges and scalability of today’s complex data environment. Furthermore, Apache Pulsar’s distinctive architecture separates the message serving component from the message storage segment, creating a robust cloud-native data-streaming platform. This architecture is designed to be both scalable and elastic, allowing for quick adjustments to fluctuating event traffic and evolving business needs, and it can scale up to accommodate millions of topics, ensuring that computation and storage remain decoupled for optimal performance. Ultimately, this innovative design positions StreamNative as a leader in addressing the multifaceted requirements of modern data streaming.

Lightstreamer acts as an event broker that is finely tuned for the internet, providing a smooth and instantaneous flow of data across online platforms. In contrast to conventional brokers, it adeptly manages the challenges posed by proxies, firewalls, disconnections, network congestion, and the inherent unpredictability of web connectivity. Its advanced streaming capabilities ensure that real-time data delivery is maintained, always finding efficient and reliable pathways for your information. Lightstreamer's technology is not only well-established but also at the cutting edge, continually adapting to remain a leader in the field of innovation. With a solid history and extensive practical experience, it guarantees dependable and effective data transmission. Users can count on Lightstreamer to provide unmatched reliability in any situation, making it an invaluable tool for real-time communication needs. In an ever-evolving digital landscape, Lightstreamer stands out as a trusted partner for delivering data seamlessly.

Engaging applications captivate users while motivating developers to innovate. To meet the growing demands of the digital landscape, consider utilizing the DataStax Astra Streaming service platform. This cloud-native platform for messaging and event streaming is built on the robust foundation of Apache Pulsar. With Astra Streaming, developers can create streaming applications that leverage a multi-cloud, elastically scalable architecture. Powered by the advanced capabilities of Apache Pulsar, this platform offers a comprehensive solution that encompasses streaming, queuing, pub/sub, and stream processing. Astra Streaming serves as an ideal partner for Astra DB, enabling current users to construct real-time data pipelines seamlessly connected to their Astra DB instances. Additionally, the platform's flexibility allows for deployment across major public cloud providers, including AWS, GCP, and Azure, thereby preventing vendor lock-in. Ultimately, Astra Streaming empowers developers to harness the full potential of their data in real-time environments.