head to head · open source
kafka vs nats-server
kafka has 34,117 GitHub stars, 15,657 forks, 574 open issues and last shipped yesterday. nats-server has 20,989 stars, 2,025 forks, 472 open issues and last shipped yesterday. kafka leads on adoption by 63% (34,117 vs 20,989 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 10%. 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 | 2026-11-02 | 2026-11-02 |
| 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 used by thousands of companies for high performance data pipelines, streaming analytics, data integration, and mission critical applications. You need to have Java installed. We build and test Apache Kafka with Java versions 17 and 25. The release parameter in javac is set to 11 for the clients and streams modules, and 17 for the rest, ensuring compatibility with their respective minimum Java versions. Similarly, the release parameter in scalac is set to 11 for the streams modules and 17 for the rest. Scala 2.13 is the only supported version in…
read the full kafka overview →
About nats-server
NATS is a simple, secure and performant communications system for digital systems, services and devices. NATS is part of the Cloud Native Computing Foundation (CNCF). NATS has over 40 client language implementations, and its server can run on premise, in the cloud, at the edge, and even on a Raspberry Pi. NATS can secure and simplify design and operation of modern distributed systems. [![License][License Image]][License Url] [![Build][Build Status Image]][Build Status Url] [![Release][Release Image]][Release Url] [![Slack][Slack Image]][Slack Url] [![Coverage][Coverage Image]][Coverage Url] [![Docker…
read the full nats-server overview →
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Frequently asked questions
Is kafka or nats-server more popular?
kafka has 34,117 GitHub stars and nats-server has 20,989. 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 (34,117 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.