Is Braintrust free? What it actually costs in 2026
Braintrust's Free plan is $0 with unlimited users, projects and experiments: 1 GB of processed data and 10,000 scores a month, plus $10 of model credits. Pro is $249 a month for 5 GB and 50,000 scores.
No card required; the whole team can use it. Overages exist on Free — $4 per extra GB and $2.50 per extra 1,000 scores — so the plan stretches rather than stops. Pro adds $100 of model credits, 30-day retention then $0.50 per GB a month, and $3 per extra GB.
What the free tier actually includes
- 1 GB of processed data a month (then $4 per GB)
- 10,000 scores a month (then $2.50 per 1,000)
- $10 of model credits a month for built-in models
Where the wall is
The gigabyte. LLM traces are verbose — prompts, completions, tool calls — and an app in production logs a gigabyte fast. At that point Braintrust bills $4 per GB on Free or $249 a month for Pro's 5 GB, which is the comparison against a self-hosted tracer.
After that: Pro $249 a month: $100 model credits, 5 GB then $3 per GB, 50k scores then $1.50 per 1,000, retention beyond 30 days at $0.50 per GB a month; Enterprise custom with on-prem or hosted deployment. Qualifying startups: Pro free for 6–12 months.
Can you self-host Braintrust? No — cloud only
Braintrust's on-prem option is Enterprise only. Promptfoo, DeepEval and Ragas are open-source evaluation tools compared here and run locally.
What it actually takes to run one yourself
Real RAM against the documented minimum, monthly cost, setup time, and the one thing that catches people out.
When paying is still the right call
Stay if the dashboard is doing real work for a team that would not otherwise look at evaluation at all. A hosted UI that a product manager can read is worth more than a CLI nobody outside engineering runs, and Braintrust's trace-to-test-case workflow — pulling a real production failure straight into your regression set — is genuinely well built. Stay while your seat count is small. The tools below assume someone will own evaluation as engineering infrastructure rather than as a product surface.
What you are locked into
Low. Test cases and scoring functions are your own logic in your own repository, and the SDK integration is thin. The genuinely sticky part is historical trace data, which is worth exporting before you cancel because comparison against past runs is most of the value. Plan an export, not a migration.
If you would rather not pay: Promptfoo
Promptfoo
Prompt regressions fail the build. Declarative evals that live in CI.
Free and MIT, unlimited seats. An enterprise tier exists for larger organisations.
See all 5 Braintrust alternatives comparedCompare the free options head-to-head
Read from Braintrust Data's own pricing and documentation on 2026-09-26 — 25 days ago. Vendors change prices without notice; confirm before you commit.