Arize Phoenix vs Langfuse
A side-by-side comparison of two self-hosted self-hosted ai options — licensing, setup difficulty, resource needs, and what each one replaces.
Langfuse
Open-source observability and analytics for LLM apps
| Feature | Arize Phoenix | Langfuse |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 93 · Excellent | 98 · Excellent |
| Category | Self-Hosted AI | Self-Hosted AI |
| License | Elastic-2.0 | MIT |
| Language | Python | TypeScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 1,024 MB | 2,048 MB |
| Deployment | docker, source | docker, kubernetes, helm |
| GitHub stars | ★ 11,594 | ★ 34,989 |
| First released | 2023 | 2023 |
| Replaces | LangSmith, Helicone | LangSmith |
What are Arize Phoenix and Langfuse?
Arize Phoenix
Phoenix by Arize is an open-source observability platform for experimentation, evaluation and troubleshooting of LLM and ML applications. It runs as a self-hosted server collecting OpenTelemetry traces from AI apps.
- LLM tracing and spans
- Built-in evaluators
- OpenTelemetry-based
- Self-hostable
Langfuse
Langfuse is an open-source platform for tracing, evaluating, and monitoring LLM applications. It captures detailed traces, manages prompts, and provides analytics dashboards for production AI systems.
- LLM tracing and analytics
- Prompt management
- Evaluation tooling
- Self-hostable
Arize Phoenix vs Langfuse: key differences
Arize Phoenix is written in Python, while Langfuse is built with TypeScript. Licensing differs — Elastic-2.0 for Arize Phoenix versus MIT for Langfuse. Arize Phoenix is the lighter option, starting around 1,024 MB of RAM against 2,048 MB for Langfuse. Langfuse has the considerably larger community, at 34,989 GitHub stars versus 11,594.
Why pick each one
Choose Arize Phoenix if…
- Released under the Elastic-2.0 license
- First-class Docker support for quick deployment
- Mature project with 11.6k GitHub stars
- Written in Python
Choose Langfuse if…
- Detailed LLM tracing
- Prompt management built in
- Many SDK integrations
Watch out for
- ClickHouse and Redis required
- Some features enterprise
Frequently asked questions
Is Arize Phoenix or Langfuse better?
Neither is universally better. Langfuse has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Arize Phoenix and Langfuse free and open-source?
Yes. Arize Phoenix is licensed under Elastic-2.0 and Langfuse under MIT. Both can be self-hosted at no software cost.
Can I run Arize Phoenix and Langfuse with Docker?
Arize Phoenix: yes. Langfuse: yes.
Which is lighter on resources, Arize Phoenix or Langfuse?
Arize Phoenix has the smaller minimum footprint at 1,024 MB of RAM, compared to about 2,048 MB for Langfuse. Real-world usage depends on library size, user count, and enabled features.