head to head · open source
kafka vs nats-server
kafka has 33,750 GitHub stars, 15,521 forks, 574 open issues and last shipped yesterday. nats-server has 20,745 stars, 1,962 forks, 472 open issues and last shipped yesterday. kafka leads on adoption by 63% (33,750 vs 20,745 stars). kafka is written in Java under Apache-2.0; nats-server is written in Go under Apache-2.0. kafka has attracted 46% as many forks as stars, nats-server 9%. kafka was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| kafka | nats-server | |
|---|---|---|
| GitHub stars | ★ 34K | ★ 21K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Java | Go |
| Last push | 2026-09-18 | 2026-09-18 |
| Forks | ⑂ 16K | ⑂ 2.0K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick kafka if
- You weight community size — 34K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Java
- You value the larger contributor base for long-term maintenance
pick nats-server if
- You want the nats-server feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Go
- You evaluated both and nats-server fits your workflow better
About kafka
Apache Kafka is an open source distributed event streaming platform, written in Java and Scala, for organizations that need high performance data pipelines, streaming analytics, data integration, and mission critical applications.
read the full kafka overview →
About nats-server
nats server is the Go based, Apache 2.0 licensed server at the heart of NATS, a simple, secure and performant communications system for digital systems, services and devices, aimed at teams building distributed systems, microservices, and cloud, edge or connected vehicle deployments that need messaging without running heavyweight broker infrastructure.
read the full nats-server overview →
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Frequently asked questions
Is kafka or nats-server more popular?
kafka has 33,750 GitHub stars and nats-server has 20,745. kafka has the larger community by that measure.
Are kafka and nats-server free?
Both are open source. kafka is licensed under Apache-2.0 and nats-server under Apache-2.0. Neither carries a licence fee.
What is the difference between kafka and nats-server?
kafka is written in Java and nats-server in Go. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, kafka or nats-server?
Choose kafka if you want the larger community (33,750 stars) or its Apache-2.0 licence terms. Choose nats-server if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.