Promptfoo
Compare prompts and model outputs with repeatable evaluation cases.
Overview
Promptfoo is an open-source CLI and library for evaluating LLM applications. Install it from the official guide, define a small test set and compare outputs across configurations. It can run in development or CI; only test applications you own or are authorized to assess.
Evaluation · Testing · CI
Install for free from the official publisher
Original source & installation instructions
The CLI is free; provider calls and hosted or enterprise services can incur costs. Test data may be sent to configured model endpoints.