Braintrust vs Promptfoo
Detailed side-by-side comparison to help you choose the right tool
Braintrust
🔴DeveloperLLM Observability
Braintrust is an evals-first LLM observability platform combining production tracing, prompt playgrounds, autoevals, and Topics-based pattern discovery for teams shipping AI in production.
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FreePromptfoo
🔴DeveloperAI Evaluation
Open-source CLI and library for testing, evaluating, and red-teaming LLM prompts, models, and RAG pipelines — runs locally on your machine or in CI.
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FreeFeature Comparison
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💡 Our Take
Choose Promptfoo if your priority is developer-driven evaluation plus red-teaming, guardrails, MCP Proxy coverage, and LLM vulnerability scanning. Choose Braintrust if your team is more focused on experiment tracking, evaluation management, datasets, and production feedback loops across many AI product iterations.
Braintrust - Pros & Cons
Pros
- ✓Evals-first design with versioned datasets, side-by-side prompt comparisons, and autoevals library means iteration is the default workflow, not an afterthought
- ✓Brainstore (purpose-built for AI traces) and the official MCP server make large-scale log search and IDE-driven prompt iteration meaningfully faster than competitors
- ✓Generous Starter tier ($0/mo with 1 GB processed data, 10k scores, unlimited users/projects/datasets) lets teams ship real evals before paying anything
Cons
- ✗$249/month Pro tier is a steep first paid step versus self-hosting Langfuse, which is free if you run the open-source version on your own infrastructure
- ✗Topics token costs ($0.06/mtok input, $0.40/mtok output beyond credits) can spike quickly on chatty production traffic with custom facets
- ✗No built-in LLM gateway, prompt router, or model fallback layer — you still need OpenRouter or similar for routing and resilience
Promptfoo - Pros & Cons
Pros
- ✓Covers 6 product areas listed on the website: Red Teaming, Guardrails, Model Security, MCP Proxy, Code Scanning, and Evaluations.
- ✓Community plan is described as Free Forever and includes local or self-hosted operation, all LLM evaluation features, vulnerability scanning, and red teaming up to 10k probes per month.
- ✓Useful beyond prompt testing because it includes real-time guardrail positioning, model security monitoring, MCP Proxy protection, and IDE/CI/CD code scanning for LLM vulnerabilities.
- ✓Strong fit for regulated workflows because the website names 4 industry solution areas: Financial Services, Insurance, Telecommunications, and Real Estate.
- ✓Supports development workflows where evaluations and red-team checks can run before merge or release instead of relying only on post-deployment monitoring.
- ✓The site displays a public 20.6k metric alongside its open-source and community positioning, indicating substantial visible adoption or repository activity.
Cons
- ✗Public paid pricing is quote-based: Enterprise and On-Premise are listed as Custom rather than fixed monthly or annual prices.
- ✗The product surface is broad, so teams that only need simple prompt regression tests may find the security, guardrails, MCP proxy, and model-security positioning more than they need.
- ✗Red-teaming and evaluation quality still depend on well-designed test cases, assertions, graders, and representative datasets.
- ✗The website emphasizes development-time and security testing more than production observability, so teams may still need a tracing or monitoring platform alongside Promptfoo.
- ✗Enterprise suitability is clear, but self-serve details such as exact paid seat limits, usage caps beyond Community red-team probes, hosted data retention, and final contract terms are not visible in the public pricing content.
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