Promptfoo for Web

Product summary

Promptfoo is a web-based platform for testing and grading prompts used with large language models (LLMs). It helps teams improve prompt quality by running automated evaluations against representative user inputs and reporting objective results that reduce guesswork during prompt refinement.

Primary capabilities

• Create and run test cases made from realistic user input samples to validate prompt behavior.
• Compare multiple prompts and their model outputs side-by-side to identify the most effective formulations.
• Choose from built-in scoring methods or plug in custom evaluation metrics to match your specific success criteria.
• Maintain a searchable library of prompts and evaluations to support repeatable, consistent testing.

Deployment and workflow integration

• Seamlessly integrates into testing pipelines and continuous integration systems so prompt checks can run automatically.
• Offers both a web-based viewer for exploration and a command-line interface for automation and scripting.

Benefits for teams

• Reduces subjectivity in prompt tuning by providing repeatable, data-driven feedback.
• Speeds up iteration by highlighting which prompts produce the best outcomes across representative inputs.
• Scales with engineering and QA workflows, making prompt validation part of standard development practices.

Suggested alternative

• DraftAid — commercial option.

Proven scale and adoption

Used by LLM-powered products with a combined user base exceeding 10 million, Promptfoo is positioned as a dependable solution for organizations aiming to optimize prompt performance.