Open-source LLM observability, tracing and evals.
Evals & observabilityopen-source
Langfuse vs LangSmith
Verdict: in our “Best agent tracing & evals” ranking, Langfuse ranks #1 and LangSmith ranks #2. The table compares their verified basics; how we rank.
| Feature | Langfuse | LangSmith |
|---|---|---|
| What it is | Open-source LLM observability, tracing and evals. | Tracing, evaluation and monitoring for LLM apps. |
| Category | Evals & observability | Evals & observability |
| Pricing model | open-source | freemium |
| Integrations | API | API |
| Self-hostable | Yes | No / not listed |
| Open-source repo | langfuse/langfuse | — |
| Rank in “Best agent tracing & evals” | #1 | #2 |
| StackRank score | Not yet benchmarked | Not yet benchmarked |
| Last verified | Oct 14, 2026 | Oct 14, 2026 |
Try them
Tracing, evaluation and monitoring for LLM apps.
Evals & observabilityfreemium