promptfoo is open source and Braintrust is not, so the question is whether you want source access and the option to fork, or would rather have a vendor accountable for it.
Eval-first platform — scorers, datasets and a playground for prompt iteration.
Local eval and red-team harness that runs in CI. No account needed.
Its red-team mode doubles as your prompt-injection regression suite.
| Braintrust | promptfoo | |
|---|---|---|
| Licence | Proprietary | Open source |
| Pricing | freemium | open source |
| Self-hostable | Yes | Yes |
| Languages | Python, TypeScript | TypeScript, Python |
| Install | — | npm install -g promptfoo |
| Keys required | BRAINTRUST_API_KEY | None |
promptfoo is open source and Braintrust is not, so the question is whether you want source access and the option to fork, or would rather have a vendor accountable for it. Braintrust: Eval-first platform — scorers, datasets and a playground for prompt iteration. promptfoo: Local eval and red-team harness that runs in CI. No account needed.
Braintrust can run on your own infrastructure. promptfoo can run on your own infrastructure.
Braintrust is proprietary (freemium). promptfoo is open source (open source).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/braintrust-vs-promptfoo