If you're building an event-driven architecture, you will probably ask yourself: NATS or Kafka?
Even though both are messaging systems, they have different goals and use cases.
What is NATS?
Nats is a lightweight, simple, and very fast messaging system. It's perfect for microservices communication, IoT, and low latency scenarios.
Pros
- Easy to set up and use
- Extremely low latency (millisecond)
- Supports pub/sub, request/reply, and streaming (with JetStream)
Cons
- No message persistency by default (JetStream adds it)
- Not ideal for long message storage or heavy reprocessing
What is Kafka?
Kafka is a distributed streaming platform, great for large-scale data processing, event sourcing, and real-time analytics.
Pros
- High durability and scalability
- Strong support for message retention and replay
- Great integration with Big Data tools
Cons
- More complex to run (Zookeeper, brokers, configurations)
- Higher latency compared to nats
Comparing Nats and Kafka
| Feature | NATS | Kafka |
|---|---|---|
| Latency | Very low | Higher |
| Complexity | Low | High |
| Durability | Optional (JetStream) | Built-in |
| Delivery Guarantees | At most once / At least once* | At least once / Exactly once |
| Replay Capability | Limited | Strong |
| Scalability | High (but different) | Very high |
| Common Use Cases | Microservices, IoT | Analytics, Event Sourcing, ETL |
When to use NATS ?
- You need low latency and fast communication
- Your events are simples and short-lived
- You want a light and easy messaging system
When yo use Kafka ?
- You need long-term retention and message replay
- Event are part of your business logic (event sourcing)
- You deal with large amounts of data
Conclusion
There’s no one-size-fits-all. The right tool depends on your specific needs.
👉 Choose NATS for fast and lightweight systems.
👉 Choose Kafka for robust and scalable systems with high durability.
Top comments (1)
Perfect breakdown, super easy to follow. Honestly I overthink picks like this way too much so seeing it this clear helps a ton.