Braintrust

What it's good for

• 1

  Running evals on prompt and model changes before they ship to production

• 2

  Logging production LLM calls so debugging a bad output takes minutes

• 3

  Iterating on prompts in a playground with side-by-side output comparison

• 4

  Bringing non-engineer reviewers into the eval loop without per-seat cost

• 5

  Benchmarking a new model or provider against your current one on real data

Pricing

• Starter

  1GB traces, 10k scores

  Free

• Pro

  Unlimited users

  $249/mo

• Enterprise

  Self-host option, compliance, support

  Custom

How to use it

Instrument your app with the Braintrust SDK so production calls are logged, then promote interesting real examples into eval datasets. Write scoring functions (LLM-as-judge, exact match, or custom logic) and run them automatically against every prompt or model change to catch regressions. Use the playground to compare variants side by side before committing. Because Pro includes unlimited users, invite product and QA people to review results directly rather than routing everything through engineering. For regulated clients, the Enterprise tier can self-host.

Pros & cons

Frequently asked questions

• Is Braintrust free?

  There is a free Starter tier with 1GB of traces and 10,000 scores, which is enough to try it on a real project. Beyond that, Pro is $249/mo and includes unlimited users, and Enterprise is custom-priced with a self-host option. It is a commercial product, so the free tier is a starting point rather than a full plan.

• Braintrust vs LangSmith: how do they compare?

  Both are hosted eval and observability platforms for LLM apps. Braintrust's pitch is unlimited users on its Pro plan, so bringing reviewers and stakeholders into the loop does not add per-seat cost, and it benchmarks itself directly against LangSmith. LangSmith is the LangChain-team option and fits naturally if you already live in that ecosystem. Pick on pricing model and which ecosystem your stack already leans toward.

• Braintrust vs Langfuse: which should I use?

  Braintrust is the hosted-first commercial pick; Langfuse is the open-source, self-hostable one. If you want a polished managed platform with unlimited users and do not need to self-host, Braintrust fits. If owning your trace data or self-hosting for free matters more, go with Langfuse. Many teams choose based on whether data has to stay on their own infrastructure.

• What is Braintrust best for?

  Teams that want a hosted eval and observability platform and expect a lot of people (engineers, PMs, QA) in the loop. The unlimited-user Pro plan makes it a strong fit where per-seat pricing on other tools would get expensive, and the playground plus eval workflow keeps AI features from regressing silently.

• Does Braintrust support self-hosting?

  Yes, on the Enterprise tier. The Starter and Pro tiers are the hosted cloud service, while Enterprise adds a self-host option along with compliance and support features. If self-hosting is a hard requirement on a smaller budget, an open-source alternative like Langfuse may fit better.

More

• Braintrust docs
• Braintrust pricing

Alternatives to Braintrust

Other tools we'd consider for the same job.

• LangSmith

  LLM observability, tracing, and evals from the LangChain team. The piece every serious AI deployment needs before it goes wrong in production

• Langfuse

  Open-source LLM engineering platform: tracing, evals, and prompt management. The own-your-traces answer to LangSmith

Other Data & ML Ops tools

• Qdrant

  Open-source vector database with a Rust engine. Self-host for data sovereignty, or run the managed cloud with a free tier

• Langfuse

  Open-source LLM engineering platform: tracing, evals, and prompt management. The own-your-traces answer to LangSmith

• Ollama

  Free, open-source runtime for local LLMs. Run Llama, DeepSeek, Mistral and more on your own machine with one command

• Pinecone

  Fully-managed vector database for production RAG. Serverless tier, low operational overhead — the default for client deployments