The best LLM Evaluation & Testing
Every option ranked — open-source, self-hostable, and commercial — by our transparent Sovereignty Score, with honest trade-offs so you choose what fits you, not us.
How you find out whether a prompt change made things better or worse. Without it, every model upgrade is a guess. The open tools run in CI next to your unit tests; the platforms add a hosted UI and per-seat pricing.
L4Models & tooling — layer 4 of the AI stack- 1
Promptfoo
Top pickOpen sourcePrompt regressions fail the build. Declarative evals that live in CI.
Free and MIT, unlimited seats. An enterprise tier exists for larger organisations. · in our Braintrust comparison →
What is Promptfoo? →94sovereignty - 2
Inspect AI
Open sourceThe rigorous one, from the UK AI Safety Institute.
Free, MIT, publicly funded. · in our Braintrust comparison →
What is Inspect AI? →93sovereignty - 3
DeepEval
Open sourceEvals as pytest tests, with the research metrics already implemented.
Free and Apache-2.0; optional paid cloud dashboard. · in our Braintrust comparison →
What is DeepEval? →92sovereignty - 4
Ragas
Open sourcePurpose-built RAG evaluation — measures retrieval and generation separately.
Free, Apache-2.0. · in our Braintrust comparison →
What is Ragas? →92sovereignty - 5
OpenAI Evals
Open sourceThe original benchmark harness. Simple, standard, still useful.
Free, MIT. You pay for whatever model API the evals call. · in our Braintrust comparison →
What is OpenAI Evals? →85sovereignty
Is it free?
The free tier, its real limits and where you start paying — read from each vendor's own pricing page and dated.
Run these yourself
What each one actually needs — real RAM, honest running cost, and the setup time nobody quotes.
Replacing a specific tool?
Head-to-head comparisons for each popular llm evaluation & testing product.
Straight head-to-heads
Two llm evaluation & testing tools, side by side — verified facts and a plain verdict.