Both are open source observability & evals options with comparable terms, so the choice comes down to which model of the problem you prefer — compare the descriptions below rather than the licence.
Open-source tracing, prompt management and evals. Self-hostable in one compose file.
OpenTelemetry-native tracing and evals you can run locally.
| Langfuse | Arize Phoenix | |
|---|---|---|
| Licence | Open source | Open source |
| Pricing | freemium | open source |
| Self-hostable | Yes | Yes |
| Languages | Python, TypeScript | Python, TypeScript |
| Install | pip install langfuse | pip install arize-phoenix |
| Keys required | LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY | None |
Both are open source observability & evals options with comparable terms, so the choice comes down to which model of the problem you prefer — compare the descriptions below rather than the licence. Langfuse: Open-source tracing, prompt management and evals. Self-hostable in one compose file. Arize Phoenix: OpenTelemetry-native tracing and evals you can run locally.
Langfuse can run on your own infrastructure. Arize Phoenix can run on your own infrastructure.
Langfuse is open source (freemium). Arize Phoenix is open source (open source).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/langfuse-vs-phoenix