Best Event Brokers of 2025

Use the comparison tool below to compare the top Event Brokers on the market. You can filter results by user reviews, pricing, features, platform, region, support options, integrations, and more.

Overview of Event Brokers

Event brokers are systems designed to handle and manage the flow of events in a distributed network. Think of them like a traffic controller for data—ensuring that messages, signals, or changes happening in one part of a system are delivered where they need to go. Rather than having each service or component communicate directly with one another, an event broker steps in to manage and route events as needed. This helps simplify the architecture by reducing dependencies between different parts of the system, making it easier to scale and maintain.

In practical terms, event brokers make sure that events are delivered to the right service or application, even if they're operating at different speeds or on different schedules. They can handle large amounts of data at once, ensuring that no messages are lost, and can even store events temporarily if the receiver isn’t ready to process them immediately. This is especially important in environments where services are constantly changing or adapting. With tools like Kafka or RabbitMQ, event brokers also help developers monitor, control, and troubleshoot the flow of events, making them a critical piece of building efficient and resilient systems.

What Features Do Event Brokers Provide?

1. Guaranteed Event Delivery: Event brokers ensure that messages or events are reliably delivered, even if there’s a system failure or network issue. This guarantee can be configured in various ways, such as ensuring that events are retried or stored until successful delivery occurs. This is essential in mission-critical systems where losing events can lead to significant problems or financial loss.
2. Event Filtering: Brokers allow consumers to filter out events they don’t need, often by topics, tags, or content types. By doing so, they reduce unnecessary load on consumers, letting them focus only on relevant events. This is especially helpful when there’s a large volume of events, ensuring consumers aren’t overwhelmed with irrelevant data.
3. Fault Tolerance: Fault tolerance means the broker can continue functioning even if parts of the system experience failures. For example, if one server goes down, another can pick up the load, ensuring that event processing doesn’t stop. This is a key feature for high-availability systems where even brief downtime can have a serious impact.
4. Scalable Architecture: Event brokers are built to scale easily, meaning as your system grows and more events are generated, the broker can handle the increased load without breaking a sweat. They can distribute workloads across multiple instances or clusters to ensure smooth performance. Scalability is a game-changer for systems expecting to grow in size or complexity, allowing for continuous expansion without hitting bottlenecks.
5. Real-Time Processing: Many event brokers process events as soon as they’re created, which is vital for systems where timely responses are necessary. This enables things like real-time analytics, instant notifications, or rapid transaction processing. If your application requires instant feedback based on real-time data, this feature is non-negotiable.
6. Asynchronous Event Handling: Event brokers handle communication asynchronously, meaning that the system doesn’t need to wait for a response before moving on to the next task. Producers can continue creating events without waiting for consumers to process them, making the system much more efficient. This leads to faster throughput and a more responsive system, especially in high-demand environments.
7. Message Ordering: When dealing with sequences of events that must be processed in order, event brokers can enforce the correct order of delivery. This is crucial when one event depends on the state of another, ensuring nothing gets missed or out of sync. It's particularly useful in processes where operations must follow a logical sequence, like ecommerce transactions or state transitions in a system.
8. Event Replay and History: Event brokers often allow you to replay or look back at past events. This is helpful for debugging, recovering lost information, or reprocessing events if something went wrong. In industries where tracking the complete history of events is important (like finance or healthcare), having access to past events can be a lifesaver.
9. Secure Communication: Security is a major concern when dealing with sensitive data. Event brokers usually provide encryption, authentication, and authorization features to ensure that events are safely transmitted and that only authorized consumers can access them. This helps protect data integrity and privacy, keeping your system secure against malicious actors.
10. Dead Letter Queues (DLQ): When an event cannot be processed (perhaps due to an error or a consumer being unavailable), it’s moved to a Dead Letter Queue. This ensures that the event isn’t lost and can be reviewed later to determine the issue. It’s a fail-safe mechanism that gives you a second chance to address issues that might otherwise cause data loss or system errors.
11. Support for Multiple Protocols: Event brokers are often designed to work with various protocols, like MQTT, AMQP, or HTTP. This flexibility ensures that different systems, regardless of their underlying architecture, can still communicate and share events without compatibility issues. This feature is crucial in environments where systems from different vendors or technologies need to work together.
12. Consumer Load Balancing: Event brokers can distribute events evenly across multiple consumers, preventing any single consumer from being overwhelmed. This ensures better performance and ensures that consumers get the right amount of work to process. It’s especially beneficial when you have high traffic or numerous consumers, as it ensures that no consumer becomes a bottleneck.
13. Monitoring and Analytics: Most modern brokers come with built-in monitoring tools that help track the health and performance of the system. This includes event throughput, latency, and delivery success rates. By keeping an eye on these metrics, you can quickly identify issues and optimize your system before they turn into serious problems.
14. Event Transformation: In some cases, event brokers allow you to transform the content of an event before sending it to consumers. This might involve converting formats, filtering out unnecessary data, or adding information. This is valuable when you need to make data from one system compatible with another or when certain data points need to be enriched before reaching the consumer.
15. Event Aggregation: Brokers can also combine multiple events into a single one before sending them to a consumer. This is useful for systems that want to reduce the number of events handled or when several smaller events are related and should be processed together. Event aggregation helps reduce the overhead on consumers, ensuring that they don’t need to deal with numerous smaller events when one larger event would suffice.

Why Are Event Brokers Important?

Event brokers play a crucial role in modern software architectures by making communication between different systems and services smooth and efficient. In a world where applications are often spread across multiple microservices, APIs, and cloud environments, an event broker ensures that these systems can share information without being tightly coupled to one another. This decoupling helps to prevent a bottleneck where services rely on one another to function correctly, allowing each component to operate independently while still staying in sync with the overall system. It helps reduce the complexity of communication and enables flexibility, especially when building scalable, resilient, and fault-tolerant applications.

Without event brokers, it would be difficult to manage the flow of events, especially as the volume of data and services grows. These brokers help to guarantee that events are delivered even when a service goes down, ensuring that no information gets lost in the shuffle. They also allow for real-time processing, so the system can quickly react to new data or changes. In short, event brokers are a vital piece of infrastructure that keeps data flowing smoothly, enables quick responses, and ensures that systems can evolve or scale without risking failure or chaos.

Reasons To Use Event Brokers

1. Efficient Communication Between Distributed Systems: Event brokers let different parts of your system communicate without requiring them to know about each other directly. In a distributed setup, you often have services that don't need to interact in real time, but they still need to share information. An event broker handles this by allowing one service to publish events, while others can subscribe to them and process them when needed. This helps avoid direct point-to-point communication and makes things smoother.
2. Handle High Traffic without Overloading: If your system starts dealing with a lot of traffic, whether it's from more users or more events being generated, event brokers are great at handling that surge. They help manage the load by distributing events efficiently to consumers who are ready to process them. This means you don’t overwhelm any part of the system, and it can scale dynamically as needed.
3. Enabling Real-Time Reactions: In some cases, your applications need to respond to changes immediately—think about notifications, alerts, or any data-driven triggers. With an event broker, when something significant happens, services can react to those events in real time. It’s like an instant pipeline where events move through, and consumers can jump in and take action right away.
4. Simplifying Complex Systems: When your system is made up of many different components, keeping them connected directly can get messy. Instead of worrying about how one service sends a request to another or how they synchronize, an event broker acts as a neutral intermediary. This not only simplifies how different pieces of your architecture talk to each other but also helps keep everything clean and easy to manage.
5. Supports Scalability Without Major Overhaul: As your application grows, you might find that you need to add more services, features, or even new types of events. Event brokers give you the flexibility to scale up without completely redoing how your system works. You can add new consumers or producers of events, and the broker will handle the rest without requiring you to rebuild the infrastructure.
6. Built-In Fault Tolerance: With event brokers, you get automatic safeguards against failures. If something goes down, the broker can store messages temporarily (depending on your configuration) until everything is back up and running. It’s like a buffer that ensures you don’t lose data and allows systems to recover smoothly without dropping important information.
7. Decouple Dependencies Between Services: Directly linking services can create tight dependencies, which can cause problems when one service has to be updated, moved, or replaced. An event broker decouples services, meaning that changes to one service don't directly affect the others. Each service just listens for or sends events as needed, without worrying about how the other services are structured.
8. Improve Performance with Asynchronous Processing: Event brokers allow services to process events asynchronously, meaning they can work on tasks without waiting for responses. This makes systems faster because services don’t have to sit idle waiting for another service to respond. Instead, they can focus on their own job while letting the broker handle the routing and delivery of events.
9. Maintain Historical Data for Replay or Auditing: Sometimes it’s helpful to look back at what happened in the system at a certain point in time. Event brokers can store events and allow them to be replayed if needed. This can be useful for debugging, recovering from errors, or even auditing, as you can track how data flowed through the system at any given moment.
10. Smoother Integration Between Different Technologies: Not all services run on the same platforms or technologies. You might have services running on different languages or frameworks, and getting them to talk directly can be tricky. Event brokers can smooth over these differences by providing a common way to handle events, no matter what tech stack your services are running on. This means you can integrate new systems and services without much hassle.
11. Customizable and Flexible Event Processing: Event brokers give you a lot of flexibility in how events are processed. You can filter events, transform them, or even aggregate them before they get to the consumer. This lets you tailor how events are handled based on what makes sense for your use case, without locking you into rigid structures.
12. Avoid Unnecessary Polling: Traditional systems often rely on polling, where one service has to keep asking another if there's anything new to process. This can be inefficient and lead to wasted resources. Event brokers get rid of that need by pushing events only when there’s something to process. This saves time, reduces load on the system, and improves overall efficiency.
13. Boost Developer Productivity: With event brokers in place, developers can focus more on their service’s core logic without worrying about how to directly connect or manage interactions with other services. By handling communication and message delivery behind the scenes, event brokers streamline workflows and reduce the complexity of building and maintaining systems.
14. Create a More Responsive System: If your application needs to respond quickly to user actions, such as sending real-time updates, notifications, or live data feeds, an event broker makes it easy. Services can react to events as soon as they occur without delay, making your system much more responsive and user-friendly.
15. Cost-Effective Architecture: Using an event broker can actually save costs in the long run. By optimizing communication and reducing the need for tight integrations or complex point-to-point connections, you end up with a more cost-efficient infrastructure. Plus, with built-in scalability, you only pay for what you need as your traffic grows.

Who Can Benefit From Event Brokers?

• Developers in Distributed Systems: Developers working with microservices or distributed systems love event brokers because they make it easier to decouple components. This means different parts of the system can communicate without directly talking to each other, which improves scalability and fault tolerance. Developers can use event brokers to handle large volumes of data asynchronously, making systems faster and more reliable.
• IT Operations Teams: Event brokers can be a game changer for IT operations teams. By automatically sending alerts and notifications about system performance or failures, event brokers help these teams stay ahead of issues. This allows them to respond quicker and troubleshoot problems before they cause significant downtime, making their workflows much more proactive and less reactive.
• Marketing Automation Specialists: Marketing teams looking to create personalized customer journeys use event brokers to trigger targeted actions in real time. If a customer opens an email or abandons a shopping cart, event brokers can send signals that activate personalized offers or follow-ups. This real-time event handling makes marketing campaigns more relevant and timely, improving engagement and conversion rates.
• Data Engineers and Analysts: For data engineers, event brokers help streamline the process of collecting, processing, and routing massive amounts of real-time data from various sources. These teams rely on event brokers to ensure data flows smoothly into the correct pipelines, which is key for building and maintaining effective analytics or machine learning models. This real-time data streaming is crucial for any analysis that needs to be up-to-the-minute accurate.
• Business Operations Leaders: Those in charge of business operations can use event brokers to create more streamlined and automated workflows. By monitoring key business events like inventory levels or customer orders, event brokers can trigger specific actions across the organization’s systems. For example, they can automatically update a CRM when a sales opportunity changes status or notify inventory systems when stock is low.
• Product Development Teams: Product teams can use event brokers to stay connected with real-time product data. When a feature or update gets released, event brokers allow the team to track user interactions and instantly respond to customer feedback. This keeps the product development cycle agile, as teams can adapt and iterate on features faster based on live usage data.
• Customer Support Representatives: Customer support teams can keep a pulse on customer issues by receiving real-time event updates about ongoing tickets or system statuses. For example, if an outage is reported, the team can automatically be notified and can act fast to resolve customer concerns. It ensures that they are always aware of the latest issues, giving them the ability to provide faster and more effective solutions.
• Security Teams: Event brokers are essential for security professionals monitoring suspicious activities across networks and systems. Security systems can send events (like unauthorized login attempts) through the event broker, which triggers an immediate response, such as locking an account or notifying a security officer. This level of real-time detection helps prevent breaches and secures data quickly.
• Third-Party Integrators: Service integrators—those connecting multiple software or platforms—rely on event brokers to sync up systems that need to communicate with each other. This is especially useful when integrating third-party APIs, payment systems, or different enterprise applications. Event brokers help make the communication between systems smooth and reliable, reducing integration complexity.
• CIOs and CTOs: Chief Information and Technology Officers use event brokers as a foundational part of a company’s digital transformation. They help drive innovation by making it possible to build highly scalable, flexible, and responsive systems. Event brokers enable organizations to adopt event-driven architectures, which are vital for staying competitive in fast-changing markets.
• eCommerce Managers: eCommerce platforms can get a lot of value from event brokers by using them to monitor key events like purchases, cart abandonment, or customer registration. These events can trigger actions like sending order confirmations, initiating customer support tickets, or activating promotions. This level of automation makes online retail environments faster and more dynamic.
• Enterprise Architects: For enterprise architects designing large-scale IT infrastructure, event brokers simplify the complexity of managing communication between different parts of the organization. By facilitating event-driven architectures, event brokers enable these architects to ensure that systems are responsive, scalable, and able to adapt to new business needs without major reworking.
• Cloud Engineers: Cloud engineers benefit from event brokers by leveraging them to manage cloud-based services and serverless architectures. They help scale and manage communication between services in cloud environments where traditional point-to-point connections aren’t efficient or scalable. This is especially useful when managing complex cloud-native systems with various microservices or hybrid architectures.

How Much Do Event Brokers Cost?

Event brokers can come with a wide range of price tags depending on your needs. For smaller businesses or those just starting with event-driven architectures, you might find more affordable cloud-based solutions. These usually follow a pay-as-you-go model, where the cost scales with your usage—typically based on things like the number of events processed or how many clients you're connecting. For these services, you could expect monthly fees that can be as low as a couple hundred bucks, but as your needs grow, so does the price. The more events you push through, the more you'll pay, but there are also features or add-ons you might need that can drive up costs, such as advanced analytics or greater data retention.

On the other hand, larger companies or those requiring highly customized setups often pay much more for their event broker solutions. When you're looking at enterprise-grade event brokers, the costs can go well into the thousands or even tens of thousands per month. Some of this is due to the fact that you might need to deploy the broker on your own infrastructure, which means you’re also responsible for maintenance, scaling, and support. Additionally, licensing for these systems can involve annual fees, and some platforms have charges for additional features like data redundancy or support for massive scale. If you’re dealing with complex integration or high-volume event streams, you’re likely looking at a significant investment in both time and money.

What Do Event Brokers Integrate With?

Event brokers can work with a wide range of software systems that need to handle or react to data in real-time. For instance, applications built using event-driven architecture, such as microservices, commonly rely on event brokers to facilitate communication between different parts of a system. These services send and receive messages based on events, which allows them to stay loosely coupled while maintaining the flow of information. Additionally, many cloud-native applications built on platforms like AWS, Azure, or Google Cloud leverage event brokers to manage data streams, triggering specific actions like function executions or cloud resource adjustments whenever certain events occur.

Another type of software that integrates with event brokers is enterprise applications such as CRMs, ERPs, and business intelligence tools. These systems often need to keep various parts of the business running smoothly and in sync, so event brokers help them react to changes in real time, whether that’s a customer making a purchase or an order status being updated. Many workflow automation tools also rely on event brokers to kick off processes or connect systems, ensuring seamless operation between departments. Additionally, big data platforms and real-time analytics tools use event brokers to collect and process data quickly, enabling fast decision-making based on up-to-the-minute information.

Risks To Consider With Event Brokers

• Single Point of Failure: When an event broker fails, the entire communication system can come to a halt. If not properly designed with redundancy and failover mechanisms, the failure of a broker can disrupt all processes relying on it, causing downtime and impacting business operations.
• Event Duplication: In certain situations, events may be processed multiple times due to misconfigurations, network issues, or retries. This duplication can lead to inconsistencies in downstream systems, creating problems in data integrity and potentially causing errors or mismatches in business logic.
• Data Loss: Event brokers store and process events temporarily before passing them along to the appropriate consumers. If these brokers aren't properly configured or if there is a failure (like a crash or network outage), there’s a risk that events could be lost, which might result in missed updates, incomplete processing, or inaccurate data in systems.
• Scalability Issues: Although event brokers are designed to handle large volumes of events, they can become overwhelmed if the system isn’t properly scaled. Without considering proper capacity planning, you risk hitting performance bottlenecks, where the broker struggles to handle a high number of incoming events, resulting in delays or system crashes.
• Security Vulnerabilities: Event brokers transmit sensitive data, making them potential targets for cyberattacks. Poor encryption, lack of authentication, and insecure data transport can expose systems to risks like data breaches, unauthorized access, and man-in-the-middle attacks, compromising both data and the integrity of the event-driven architecture.
• Latency Problems: If an event broker is poorly optimized or overwhelmed by traffic, the time it takes to transmit events can increase. Latency issues can disrupt time-sensitive operations, especially in industries like finance or healthcare, where processing speed is critical.
• Complexity of Management: While event brokers are useful, they can be challenging to manage, especially when operating at scale. Proper configuration, monitoring, and maintenance are necessary to ensure they perform optimally. With large systems, this complexity can lead to misconfigurations, overlooked issues, or delays in addressing operational problems.
• Data Consistency Challenges: In distributed systems, it’s common for events to be consumed by multiple services. Without strong mechanisms for ensuring consistency, different services might process the same event in conflicting ways, leading to inconsistent state across the system. This can create confusion and potentially lead to incorrect outcomes.
• Difficulty in Troubleshooting: When issues arise within an event-driven system, pinpointing the exact cause can be a nightmare. Event brokers distribute data between different services, which may be running on different infrastructures. Tracking down the root cause of an error becomes increasingly difficult, especially in large, complex ecosystems, leading to longer resolution times.
• Overhead of Message Serialization: For event brokers that deal with complex data structures, serializing messages to and from formats like JSON or Avro can add significant overhead. The conversion process takes time and resources, and if the serialization/deserialization process isn't optimized, it can cause performance degradation.
• Dependency on Network Stability: Event brokers heavily rely on network communication between services. If the network suffers from latency or connection failures, the broker’s ability to deliver events promptly is compromised. This creates a risk of delayed or lost messages, which can affect time-sensitive processes.
• High Operational Costs: Maintaining an event broker infrastructure, particularly when scaling, can become expensive. The costs associated with storage, data transfer, and scaling for high availability or fault tolerance can quickly add up. Organizations need to carefully assess whether the benefits outweigh the operational overhead in terms of costs.
• Event Broker Mismanagement: Incorrect configurations, such as improper topic or partitioning setup, can lead to inefficient use of system resources. Poor management of event consumers (like over-subscribing or under-subscribing to events) can degrade the overall performance of the event-driven system.
• Vendor Lock-in: Relying on a specific event broker or cloud-based service can create long-term dependencies. If the system is built around a particular platform, moving to another provider can be costly and complex. Vendor-specific tools and APIs can lock organizations into a single ecosystem, limiting flexibility and future options.
• Data Privacy Risks: If not configured properly, event brokers can inadvertently expose personal or sensitive data to unauthorized entities. Without encryption, access control, or the necessary privacy safeguards, there's a chance that private information could leak during transmission or storage, leading to privacy violations.

Questions To Ask When Considering Event Brokers

1. How does the event broker handle failure and recovery? Event-driven systems are highly dependent on continuous uptime, and any downtime can have a significant impact. Ask how the event broker handles failures and ensures data durability. Does it offer automatic failover or replication to prevent data loss during a crash or outage? It’s important to understand whether it provides options to recover without disrupting the service, as this directly affects the reliability of your system.
2. What kind of message delivery guarantees does it offer? Depending on the use case, your system might need different types of message delivery guarantees. Some applications require "at least once" delivery, while others might need "exactly once" or "at most once" delivery to avoid duplicates or message loss. Ask the vendor or look at the documentation to see which guarantees are offered and whether they align with your needs. Without this clarity, you could face unexpected issues in message handling.
3. How well does the broker integrate with my current technology stack? Integration is key when adopting any new tool. Find out how easily the event broker integrates with your existing system. Does it support the programming languages, frameworks, or platforms that your team is already using? The more compatible it is with your tech stack, the less friction there will be when deploying and maintaining the system. Consider whether it has APIs, SDKs, or connectors that will make integration easier.
4. Is the broker scalable to meet future demands? Systems evolve, and what works for you today may not work tomorrow as your traffic or event volume increases. Ask about how the broker handles scaling—can it easily scale horizontally or vertically as your needs grow? Does it offer auto-scaling capabilities? You'll want to ensure that, as your system grows, the event broker can keep up without causing delays or performance bottlenecks.
5. What kind of monitoring and debugging tools does it offer? Having insights into the event flow, system performance, and any issues is vital for troubleshooting. Look for brokers that come with built-in monitoring or logging features. Does it allow you to track event statuses, track errors, or visualize event traffic? You’ll need to ensure you can identify problems before they become critical and respond to issues quickly.
6. What is the total cost of ownership? While upfront costs matter, don’t overlook the total cost of ownership (TCO) when evaluating an event broker. Ask about any hidden fees, maintenance costs, or pricing based on event volume. Some brokers charge for the number of messages sent, while others charge based on throughput or data retention. Make sure the pricing model fits within your budget, both in the short and long term, considering potential scaling needs.
7. Does it support a variety of messaging patterns and protocols? Event brokers can support different types of messaging patterns such as publish-subscribe, point-to-point, or stream processing. Ask which types of messaging patterns it supports, and if it’s flexible enough for the specific needs of your system. Additionally, ask about the protocols it supports (like Kafka, MQTT, AMQP, etc.). The more flexible it is in terms of messaging patterns and protocols, the more adaptable it will be to your system’s requirements.
8. How does it ensure message ordering and consistency? In certain applications, message ordering is critical. Find out how the event broker handles message ordering and whether it guarantees message consistency across distributed systems. For instance, does it support partitioning to ensure that messages within a specific partition are processed in order? This can be a make-or-break feature depending on your use case.
9. What is the learning curve for the team? Consider the skill set of your team when choosing an event broker. Some brokers are more complex than others and might require specialized knowledge or extra training to operate effectively. Ask about the learning curve—does it offer an intuitive UI, clear documentation, and good community support? A tool that’s easy to use can reduce the time your team spends troubleshooting or figuring out how things work.
10. What security features are available? Security is always a top priority. Inquire about the event broker’s built-in security features. Does it offer encryption for data at rest and in transit? Are there user authentication and access control mechanisms in place? You’ll want to ensure the event broker meets your security standards, especially if it handles sensitive data or integrates with other parts of your infrastructure.