head to head · open source
zipkin vs cost-xray
zipkin has 17,464 GitHub stars, 3,098 forks, 175 open issues and last shipped 2 months ago. cost-xray has 2,107 stars, 214 forks, 13 open issues and last shipped 19 days ago. zipkin leads on adoption by 729% (17,464 vs 2,107 stars). zipkin is written in Java under Apache-2.0; cost-xray is written in Python under MIT. zipkin has attracted 18% as many forks as stars, cost-xray 10%. cost-xray was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (observability), so they are genuine substitutes rather than adjacent tools.
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
| zipkin | cost-xray | |
|---|---|---|
| GitHub stars | ★ 17K | ★ 2.1K |
| License | Apache-2.0 | MIT |
| Written in | Java | Python |
| Last push | 2026-08-06 | 2026-09-01 |
| Forks | ⑂ 3.1K | ⑂ 214 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick zipkin if
- You weight community size — 17K 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 cost-xray if
- You want the cost-xray feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Python
- You evaluated both and cost-xray fits your workflow better
About zipkin
Zipkin is a distributed tracing system maintained under the OpenZipkin organization and written in Java, released under the Apache 2.0 license. It lives in the Java and JVM ecosystem as a standalone server, while its instrumentation libraries span many languages. The project gathers the timing data needed to troubleshoot latency problems in service architectures, and it covers both the collection and the lookup of that data.
read the full zipkin overview →
About cost-xray
cost xray is an MIT licensed open source observability proxy for Claude Code and Codex that captures the API traffic those agents actually send and attributes every token and dollar back to the system prompts, tool schemas, MCP blocks, tool results, cache reads and writes, and thinking blocks that produced them.
read the full cost-xray overview →
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Frequently asked questions
Is zipkin or cost-xray more popular?
zipkin has 17,464 GitHub stars and cost-xray has 2,107. zipkin has the larger community by that measure.
Are zipkin and cost-xray free?
Both are open source. zipkin is licensed under Apache-2.0 and cost-xray under MIT. Neither carries a licence fee.
What is the difference between zipkin and cost-xray?
zipkin is written in Java and cost-xray in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, zipkin or cost-xray?
Choose zipkin if you want the larger community (17,464 stars) or its Apache-2.0 licence terms. Choose cost-xray if its feature set, stack or MIT licence fits better. Both are self-hostable.