Braintrust vs. Promptfoo: 2026 LLM evaluation comparison

Promptfoo and Braintrust are two distinct platforms designed for evaluating large language models (LLMs), each catering to different needs in the AI development and production lifecycle. Promptfoo is an open-source, CLI-first tool ideal for developer-led workflows, offering deep red teaming and security testing within a local or CI environment, with YAML-based configuration stored alongside code. It emphasizes open-source control and extensive security test coverage, making it suitable for environments focused on red teaming and security. In contrast, Braintrust is a comprehensive AI evaluation and observability platform that integrates seamlessly with production environments, offering features like production tracing, evaluation, CI/CD quality gates, and continuous improvement. It supports shared workflows across engineering, product, and operations teams, allowing for real-time production monitoring, trace analysis, and regression testing built from actual production failures. Braintrust's pricing is transparent, with a free Starter plan and a Pro plan that scales with production needs, whereas Promptfoo may require custom Enterprise pricing for broader deployment. While both platforms can complement each other, Braintrust generally provides a more robust solution for teams needing integrated production observability and quality control, whereas Promptfoo excels in security-focused, terminal-based workflows.