Head-to-head comparison
LangfusevsLangSmith
The two leading observability platforms for LLM applications. LangSmith is built by the LangChain team and integrates tightest with that ecosystem. Langfuse is open source, framework-agnostic, and can be self-hosted.
At a glance
| Langfuse | LangSmith | |
|---|---|---|
| Category | Coding | Coding |
| Function | LLM observability | LLM observability |
| Pricing | Freemium | Freemium |
| Starting price | Free Hobby cloud tier and self-hosting; Core from $59/mo | Free 5k traces/mo, Plus $39/mo |
| Released | May 2023 | July 2023 |
Langfuse
Pros
- Fully open source with a generous free tier
- Framework-agnostic — works with plain SDK calls too
- Prompt management and evals in the same tool as tracing
Cons
- Self-hosting requires Postgres and ClickHouse to run well
- UI is dense for non-technical stakeholders
- Younger than LangSmith in some enterprise features
LangSmith
Pros
- Industry-standard tracing for LangChain users
- Strong eval framework
- Free tier good for prototyping
Cons
- Tied to LangChain ergonomics (still works without)
- Self-hosted is enterprise-only
- Some features paywalled
Which one should you pick?
Pick Langfuse if
You want open source, self-hosting or data residency, and a tool that works equally well with plain SDK calls as with any framework.
See Langfuse details →Pick LangSmith if
You build on LangChain or LangGraph and want the deepest integration, plus polished evaluation and dataset tooling from the same team.
See LangSmith details →Bottom line
Langfuse for open-source, framework-neutral teams. LangSmith for LangChain shops. Both do tracing, evals, and prompt management well.