DeepEval 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 | DeepEval | Langfuse |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Health score | 95 · Excellent | 98 · Excellent |
| Category | Self-Hosted AI | Self-Hosted AI |
| License | Apache-2.0 | MIT |
| Language | Python | TypeScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 1,024 MB | 2,048 MB |
| Deployment | source | docker, kubernetes, helm |
| GitHub stars | ★ 18,419 | ★ 34,989 |
| First released | 2023 | 2023 |
| Replaces | LangSmith, Braintrust | LangSmith |
What are DeepEval and Langfuse?
DeepEval
DeepEval is an open-source evaluation framework that brings unit-testing-style assertions to large language model outputs. It includes metrics for hallucination, relevancy, and bias and integrates with pytest for local CI.
- Pytest-style LLM tests
- 14+ built-in metrics
- Synthetic dataset generation
- CI/CD integration
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
DeepEval vs Langfuse: key differences
DeepEval is written in Python, while Langfuse is built with TypeScript. Licensing differs — Apache-2.0 for DeepEval versus MIT for Langfuse. DeepEval is the lighter option, starting around 1,024 MB of RAM against 2,048 MB for Langfuse. Langfuse lists first-class Docker deployment; DeepEval does not.
Why pick each one
Choose DeepEval if…
- Pytest-style LLM tests
- Rich metric library
- Runs in CI
Watch out for
- LLM judge token costs
- Cloud platform upsell
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 DeepEval 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 DeepEval and Langfuse free and open-source?
Yes. DeepEval is licensed under Apache-2.0 and Langfuse under MIT. Both can be self-hosted at no software cost.
Can I run DeepEval and Langfuse with Docker?
DeepEval: check the project docs for container support. Langfuse: yes.
Which is lighter on resources, DeepEval or Langfuse?
DeepEval 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.