Braintrust vs LangSmith: Which is Better in 2026?
Choosing between Braintrust 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. LangSmith is cheaper to start, but the right choice depends on the specific features and integrations you need.
Braintrust vs LangSmith — Side by Side
| Braintrust | LangSmith | |
|---|---|---|
| Category | LLM Observability & Evals | LLM Observability & Evals |
| Pricing | Free · paid from $249/mo | Free · paid from $39/seat/mo |
| Starting price | Free tier available | Free tier available |
| Free tier | ||
| Rating | 4.6 | 4.5 |
| Best for | LLM Observability & Evals — llm, evals | LLM Observability & Evals — llm, observability |
Pros & Cons
- Strongest eval and experiment workflow in the category
- Unlimited users, so PMs and domain experts can review outputs
- Generous startup program
- $0 to $249 is a steep step with nothing in between
- Closed source, and only Enterprise can self-host
- Short default retention on both self-serve plans
- 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
Braintrust
- 5 GB processed data (+$3/GB)
- 50k scores (+$1.50 / 1k)
- 30-day retention
- Unlimited users
- 6–12 months free for qualifying startups
LangSmith
- 10,000 base traces / month included
- Pay as you go beyond that
- Unlimited seats
- Extended 180-day retention available
Choose Braintrust if…
- You want a free tier to validate before paying.
- Strongest eval and experiment workflow in the category
- Unlimited users, so PMs and domain experts can review outputs
- Generous startup program
Choose LangSmith if…
- You want a free tier to validate before paying.
- Budget is tight — paid plans start lower ($39/mo vs $249/mo).
- Best-in-class visibility into LangGraph and LangChain agents
- Mature evals, datasets and annotation queues
Frequently Asked Questions
Is Braintrust better than LangSmith?⌄
Both are solid llm observability & evals options. LangSmith is cheaper to start, but the right choice depends on the specific features and integrations you need.
What is the difference between Braintrust and LangSmith?⌄
Braintrust — Eval-first AI observability with unlimited users on every plan. It is priced on data processed and scores run, not seats. 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.
Braintrust vs LangSmith: which is cheaper?⌄
Braintrust pricing: Free · paid from $249/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, Braintrust or LangSmith?⌄
In our catalog, Braintrust rates 4.6 out of 5 and LangSmith rates 4.5 out of 5, so Braintrust has a slight edge on reviews.
See more options in our guide to the best llm observability & evals tools for startups.
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