Capability · Comparison

MLflow LLM Evaluate vs Promptfoo

MLflow LLM Evaluate (Databricks) and Promptfoo (open source) are two evaluation tools that overlap but fit different teams. MLflow LLM Evaluate extends the MLflow tracking server with LLM-specific evaluators, judges, and artifact logging — great if you already live in MLflow for classical ML. Promptfoo is a CLI + YAML tool built for fast prompt iteration and CI integration.

Side-by-side

Criterion MLflow LLM Evaluate Promptfoo
Primary interface Python API YAML + CLI + web UI
CI integration Via Python / scripts First-class — GitHub Actions, GitLab CI
Judge models Any LLM via MLflow Any LLM via config
Tracking MLflow tracking server Local JSON + optional cloud
Dataset management MLflow datasets + artifacts YAML + CSV
Human review Via MLflow UI Web UI with pass/fail annotation
License Apache 2.0 MIT
Best for Enterprise ML teams already on MLflow Prompt engineers in tight iteration loops

Verdict

If your ML org already uses MLflow for classical model tracking and you want LLM eval in the same pane of glass — MLflow LLM Evaluate. If you're a small team or an individual prompt-engineer iterating on LLM prompts in CI — Promptfoo. They can coexist: run Promptfoo in the dev loop for fast iteration, then promote final evals into MLflow for ops tracking.

When to choose each

Choose MLflow LLM Evaluate if…

  • Your org runs MLflow for traditional ML tracking.
  • You want LLM evals logged alongside classical model runs.
  • You're on Databricks or have an MLflow-first pipeline.
  • Enterprise governance and artifact lineage matter.

Choose Promptfoo if…

  • You're a developer iterating on prompts in CI.
  • You want a simple YAML-driven eval suite.
  • You value a fast web UI for diffing outputs.
  • You don't yet have an MLflow investment.

Frequently asked questions

Can I use LLM-as-judge in both?

Yes. MLflow LLM Evaluate ships judge utilities; Promptfoo has first-class LLM-rubric assertions. Both let you bring any model (OpenAI, Anthropic, local) as the judge.

Which is better for regression testing in CI?

Promptfoo — the GitHub Action is plug-and-play and produces a web-viewable diff per PR. MLflow-based CI works but requires more glue code.

Do they measure the same things?

Both support exact match, embedding similarity, LLM-as-judge rubric, and custom Python assertions. MLflow has deeper integration with traditional ML metrics; Promptfoo has more prompt-specific built-ins.

Sources

  1. MLflow — LLM Evaluate — accessed 2026-04-20
  2. Promptfoo — docs — accessed 2026-04-20