Head-to-head comparison

LangSmith vs Braintrust

LangSmith leans observability. Braintrust leans evaluation. Both stop short of shipping the fix. Here's how they compare — plus a third option for teams that want the failures resolved automatically.

At a glance

Dimension
LangSmith
Braintrust
Converra
Primary job
Trace, evaluate, debug
Evaluate & observe
Diagnose, fix & deploy
Strength
Production tracing + LangChain depth
Eval datasets + scorers
Simulation-tested fixes + rollback
Output
Traces, eval scores, datasets
Eval scores, logs, datasets
Validated prompt improvements
Iteration model
You investigate traces, you fix
You run evals, you decide changes
Diagnose + fix + validate (auto)
Testing approach
Trace-driven datasets + scorers
Custom datasets + evaluators
Head-to-head simulation
Deployment
Not included
Not included
Governed deployment + rollback
Cross-run memory
Manual tracking
Manual tracking
Learns from prior runs automatically

Deciding in 60 seconds?

  • Picking LangSmith: you want production tracing and deep LangChain integration, and you'll handle eval workflows yourself.
  • Picking Braintrust: you want eval datasets, custom scorers, and a CI/CD-friendly evaluation pipeline.
  • Picking Converra: you want the failures fixed, not just traced or scored — simulation-tested prompt improvements ship automatically.

How they actually differ

LangSmith — observability

Built around tracing. You see every step, tool call, and token in a run, with the deepest integration if you're on LangChain. Evals are dataset-driven and run on top of traces. The work of turning a bad trace into a better prompt is yours.

Braintrust — evaluation

Built around evals. You author datasets and custom scorers, wire them into CI, and watch scores over time. Strong eval discipline — but it scores the test sets you write, and deciding and shipping the change is still a human job.

Converra — the fix

Built around the improvement loop. It diagnoses the failure to a step and root cause, generates a prompt variant, tests it head-to-head in simulation, proposes a governed deployment, and verifies the result on real traffic — the part both tools leave to you.

Tracing and evals answer what happened. Converra answers what to change and whether it worked. That's the gap a third option fills — and it composes on top of whichever observability or eval tool you pick.

Frequently asked questions

Is LangSmith or Braintrust a better choice?

LangSmith is stronger for production tracing and debugging — especially if you use LangChain. Braintrust is stronger for evaluation pipelines and custom scorers. Pick LangSmith for observability depth, Braintrust for eval discipline.

Can I use LangSmith or Braintrust with Converra?

Yes. LangSmith and Braintrust give visibility and scoring. Converra closes the loop by generating, simulation-testing, and shipping fixes. They are complementary — pick the tracing or eval tool that fits, then add Converra for autonomous improvement.

What does Converra add on top of LangSmith or Braintrust?

Visibility and scoring tell you what failed. Converra tells you why, generates a prompt variant that fixes it, tests it head-to-head in simulation, and proposes deployment with rollback. The diagnose-to-fix loop closes without engineering cycles.

Why look at a third option?

If you're comparing LangSmith and Braintrust, you've already decided you need better visibility or evaluation. The next question is what to do with the failures you surface. Converra answers that — it turns those results into shipped, tested fixes.

Is Braintrust vs LangSmith the same comparison?

It's the same two tools, framed from either side. The decision doesn't change: LangSmith leans production tracing and LangChain depth; Braintrust leans eval datasets and custom scorers. Both stop at telling you what happened — neither generates, tests, or verifies the fix.

What if I just want a Braintrust alternative?

If you're shopping for a Braintrust alternative because scoring isn't reducing production failures, the alternative isn't another eval tool — it's closing the loop. Converra diagnoses the failure, ships a simulation-tested fix, and verifies it on real traffic. See the dedicated Braintrust alternative comparison for a side-by-side.

Trace it, score it — or just fix it

Connect your agent and watch Converra diagnose the failure, generate a fix, simulation-test it, and propose deployment.

Start for free