Braintrust
Braintrust is the observability and eval platform with the most explicit score pricing in the cluster: Starter is $0 with 10K scores a month, Pro jumps to $249/mo with 50K scores plus cheaper per-1K rates.
Verified against: braintrust.devbraintrust.dev as of 2026-10-03
Quick verdict: Braintrust is the pick for teams whose main cost driver is evaluation volume rather than trace volume, because it is the only vendor here that tells you the price of a scored output before you buy it and drops that rate from $2.50 to $1.50 per 1,000 when you move up. The trade-off is the gap between tiers: unlimited free usage ends at 10K scores, and the next step is $249 a month, which makes it a harder tool to grow into gradually than Langfuse or Arize AX. Pick Langfuse for a gentler price curve, Arize AX for a $50/mo middle, or LangSmith when you need tracing, evaluation and deployment in a single platform.
- Our rating: 4.2/5
- Strongest dimension: Functionality (4/5, research only)
- Weakest dimension: Localization (2/5, research only)
- Pricing: Free plan · $249/mo (Pro)
- Verification: Research-only pass over official sources, last checked 2026-10-03. Sources: braintrust.dev, braintrust.dev
Braintrust pricing details
- Free plan available
- paid plans from $249/mo (Pro)
- starter $0/mo ($10 model credits, 1 GB processed data then $4/GB, 10K scores then $2.50/1K, 14-day retention) · Pro $249/mo ($100 credits, 5 GB then $3/GB, 50K scores then $1.50/1K, 30-day retention then $0.50/GB/mo) · Enterprise custom
- no published annual rate; Pro offers 6-12 months free for qualifying startups
Scored outputs are the billing unit (LLM-as-a-judge, autoevals, custom scorers) alongside processed data and model credits; retention beyond 30 days is billed at $0.50/GB/mo up to 180 days on Pro
In our index: Starter $0/mo ($10 credits, 1 GB processed then $4/GB, 10K scores then $2.50/1K, 14-day retention) · Pro $249/mo ($100 credits, 5 GB then $3/GB, 50K scores then $1.50/1K, 30-day then $0.50/GB/mo) · Enterprise custom
How Braintrust scores across our 6 index dimensions
- Functionality: 4/5 (research only)
- Usability: 4/5 (research only)
- Stability: 4/5 (research only)
- Collaboration: 3/5 (research only)
- Localization: 2/5 (research only)
- Value: 2/5 (research only)
Score rationale: The clearest unit economics in the cluster - it tells you exactly what a score costs before you buy, and the per-1K rate drops from $2.50 to $1.50 when you move up. That transparency comes with the sharpest price jump: Starter to Pro is $0 to $249 in one step, so a team that outgrows 10K scores a month has a large decision to make rather than a gradual bill.
What Braintrust does well
- The most explicit pricing in the cluster: scores are named as the billing unit with rates ($2.50/1K on Starter, $1.50/1K on Pro), processed data and model credits are listed line by line
- Starter is genuinely free with unlimited users, projects, datasets, playgrounds and experiments - no card required
- Retention is priced rather than hidden: 14 days included on Starter, 30 on Pro, then $0.50/GB/mo up to 180 days
- 6-12 months free for qualifying startups, and an open research program with published foundations
Where Braintrust falls short
- The Starter-to-Pro step is $0 to $249/mo, so a team that crosses 10K scored outputs a month faces a large step rather than a gradual bill
- Custom charts, environments, priority support and RBAC are Pro-only, so the free tier is genuinely basic
- No S3 data export or custom retention policies until Enterprise
- The competitive table on its own pricing page concedes limited tracing and UI next to the incumbents in this set
How Braintrust compares to other LLM Observability tools
Our index tracks 5 LLM Observability tools. Braintrust sits at 4.2/5, with no published annual rate; pro offers 6-12 months free for qualifying startups. Here are the 4 closest alternatives we hold pricing and scoring evidence for.
- LangSmith — 4.4/5 · Free plan · $39/seat/mo (Plus)
LangSmith is the observability and evaluation platform from the LangChain team: $0/seat with 5K base traces a month, Plus at $39/seat with 10K, then pay-as-you-go at $1.00 per LangChain Standard Unit. - Langfuse — 4.3/5 · Free plan · $29/mo (Core)
Langfuse is the open-source-first LLM observability platform: free Hobby with 50K units a month, Core at $29/mo for 100K units and 90-day retention, Pro at $199/mo with three-year retention, Enterprise at $2,499/mo. - Arize AX — 4.0/5 · Free plan · $50/mo (AX Pro)
Arize AX is the cheapest paid step in the cluster at $50/mo, with a $0 Free tier (25K spans, 1 GB, 15-day retention) and a free open-source sibling in Arize Phoenix for fully local tracing. - Helicone — 3.8/5 · Free plan · $79/mo (Pro)
Helicone is the request-level observability and gateway layer priced per request: Hobby free with 10,000 requests a month, Pro at $79/mo, Team at $799/mo, and usage-based pricing on top.
Frequently asked questions about Braintrust
How much does Braintrust cost?
Free plan available; paid plans from $249/mo (Pro); starter $0/mo ($10 model credits, 1 GB processed data then $4/GB, 10K scores then $2.50/1K, 14-day retention) · Pro $249/mo ($100 credits, 5 GB then $3/GB, 50K scores then $1.50/1K, 30-day retention then $0.50/GB/mo) · Enterprise custom; no published annual rate; Pro offers 6-12 months free for qualifying startups. Billing detail: Scored outputs are the billing unit (LLM-as-a-judge, autoevals, custom scorers) alongside processed data and model credits; retention beyond 30 days is billed at $0.50/GB/mo up to 180 days on Pro. Figures verified 2026-10-03.
Does Braintrust have a free plan?
Yes. Braintrust has a free tier; paid plans start at $249/mo (Pro).
What is Braintrust rated in our index?
Braintrust sits at 4.2/5 in our index, strongest on functionality (4/5, research only) and weakest on localization (2/5, research only). Braintrust is the pick for teams whose main cost driver is evaluation volume rather than trace volume, because it is the only vendor here that tells you the price of a scored output before you buy it and drops that rate from $2.50 to $1.50 per 1,000 when you move up. The trade-off is the gap between tiers: unlimited free usage ends at 10K scores, and the next step is $249 a month, which makes it a harder tool to grow into gradually than Langfuse or Arize AX. Pick Langfuse for a gentler price curve, Arize AX for a $50/mo middle, or LangSmith when you need tracing, evaluation and deployment in a single platform.
What are the drawbacks of Braintrust?
The Starter-to-Pro step is $0 to $249/mo, so a team that crosses 10K scored outputs a month faces a large step rather than a gradual bill Custom charts, environments, priority support and RBAC are Pro-only, so the free tier is genuinely basic No S3 data export or custom retention policies until Enterprise The competitive table on its own pricing page concedes limited tracing and UI next to the incumbents in this set.
What does Braintrust do well?
The most explicit pricing in the cluster: scores are named as the billing unit with rates ($2.50/1K on Starter, $1.50/1K on Pro), processed data and model credits are listed line by line Starter is genuinely free with unlimited users, projects, datasets, playgrounds and experiments - no card required Retention is priced rather than hidden: 14 days included on Starter, 30 on Pro, then $0.50/GB/mo up to 180 days 6-12 months free for qualifying startups, and an open research program with published foundations.
How was Braintrust verified?
Research-only pass over official sources, last checked 2026-10-03. Sources: braintrust.dev, braintrust.dev.
What are the alternatives to Braintrust?
We track LangSmith, Langfuse, Arize AX, Helicone as the closest alternatives in our LLM Observability index, and 4 head-to-head comparisons against Braintrust are available.