Langfuse vs LangSmith: Which is Better in 2026?
Choosing between Langfuse and LangSmith? Both are popular llm observability & evals tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.
Quick verdict
Both are solid llm observability & evals options. Langfuse is cheaper to start, but the right choice depends on the specific features and integrations you need. In our catalog, Langfuse rates slightly higher (4.7 vs 4.5 out of 5).
Langfuse vs LangSmith — Side by Side
| Langfuse | LangSmith | |
|---|---|---|
| Category | LLM Observability & Evals | LLM Observability & Evals |
| Pricing | Free · paid from $29/mo | Free · paid from $39/seat/mo |
| Starting price | Free tier available | Free tier available |
| Free tier | ||
| Rating | 4.7 | 4.5 |
| Best for | LLM Observability & Evals — llm, observability | LLM Observability & Evals — llm, observability |
Pros & Cons
- Genuinely open source and self-hostable
- Unit pricing does not punish adding teammates
- Framework-agnostic: OpenTelemetry, LangChain, LlamaIndex, raw SDKs
- Prompt management and evals in the same tool as tracing
- Self-hosting at scale means running ClickHouse, Postgres and Redis
- Units add up quickly for agent traces with many spans
- Longer retention is gated behind the $199 plan
- Best-in-class visibility into LangGraph and LangChain agents
- Mature evals, datasets and annotation queues
- Accepts OpenTelemetry traces from non-LangChain code
- Per-seat and per-trace pricing both scale with you
- Trace pricing has changed repeatedly, so budgets drift
- Self-hosting requires an Enterprise contract
Key Features Compared
Langfuse
- 100k units / month included
- $8 per extra 100k units
- Unlimited users
- 90 days of data access
LangSmith
- 10,000 base traces / month included
- Pay as you go beyond that
- Unlimited seats
- Extended 180-day retention available
Choose Langfuse if…
- You want a free tier to validate before paying.
- Budget is tight — paid plans start lower ($29/mo vs $39/mo).
- Genuinely open source and self-hostable
- Unit pricing does not punish adding teammates
Choose LangSmith if…
- You want a free tier to validate before paying.
- Best-in-class visibility into LangGraph and LangChain agents
- Mature evals, datasets and annotation queues
- Accepts OpenTelemetry traces from non-LangChain code
Frequently Asked Questions
Is Langfuse better than LangSmith?⌄
Both are solid llm observability & evals options. Langfuse is cheaper to start, but the right choice depends on the specific features and integrations you need. In our catalog, Langfuse rates slightly higher (4.7 vs 4.5 out of 5).
What is the difference between Langfuse and LangSmith?⌄
Langfuse — Open-source LLM tracing, evals and prompt management: MIT-licensed, self-hostable, and $29/month in the cloud with unlimited users. LangSmith — LangChain's tracing and evaluation platform, the deepest fit for LangGraph agents. It is priced per seat plus per trace. Both are llm observability & evals tools; the comparison table above breaks down pricing, free tiers, and what each is best for.
Langfuse vs LangSmith: which is cheaper?⌄
Langfuse pricing: Free · paid from $29/mo. LangSmith pricing: Free · paid from $39/seat/mo. Confirm current pricing on each tool's official site, as plans change.
Which is rated higher, Langfuse or LangSmith?⌄
In our catalog, Langfuse rates 4.7 out of 5 and LangSmith rates 4.5 out of 5, so Langfuse has a slight edge on reviews.
See more options in our guide to the best llm observability & evals tools for startups.
Still not sure which to pick?
Get a free, AI-powered tech stack — including the best llm observability & evals pick for your budget and team — in 60 seconds.