Promptfoo vs Ragas
Both are alternatives to Braintrust. Here's how they stack up — verified facts, no spin.
Also searched as Ragas vs Promptfoo — same comparison, one verdict.
Promptfoo and Ragas are closely matched on ownership (94 vs 92) — this one comes down to pricing and to which trade-offs below you can live with.
Promptfoo
TOP PICKPrompt regressions fail the build. Declarative evals that live in CI.
Promptfoo defines evaluations as YAML: your prompts, your test cases, your assertions, versioned in the repository next to the code they test. It runs from the CLI or in CI, compares outputs across models and prompt variants side by side, and fails the build when a change regresses. It also includes red-teaming for prompt injection and jailbreak testing. MIT licensed with no seat limits, which matters because everyone who edits a prompt should be running it.
Ragas
Purpose-built RAG evaluation — measures retrieval and generation separately.
Ragas evaluates RAG systems specifically, and its central insight is that retrieval failure and generation failure need separate measurement. Context precision and recall tell you whether the retriever found the right material; faithfulness and answer relevancy tell you whether the model used it honestly. Without that separation you know the answer was wrong but not which half to fix. Apache-2.0, and it composes with LlamaIndex and Haystack directly.
Side by side
10 points of comparison, every one read from a verified field. Green marks the side that wins a row outright. A dash means we do not hold that fact — never that it is zero.
| Promptfoo | Ragas | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 94 | 92 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first data | Yes | Yes |
| License | MIT | Apache-2.0 |
| Pricing | Free and MIT, unlimited seats. An enterprise tier exists for larger organisations. | Free, Apache-2.0. |
| RAM to run it wellThe figure that actually matters, not the vendor's minimum. | 2 GB | — |
| Realistic running costWhat the box costs each month if you run it yourself. | $0. It runs in CI on hardware you already pay for. | — |
| Setup timeHonest first-install estimate, not the marketing quickstart. | 1 hour for the first ten test cases | — |
| Ongoing maintenanceThe part nobody budgets for. | Low. The suite grows with your prompts. | — |
Promptfoo is Macrostack's recommended Braintrust alternative, so it's our pick here.
Weighing both against staying on Braintrust? Is Braintrust free? What it actually costs →
Promptfoo
Strengths
- +Evals live in your repo and run in CI — a regression blocks the merge
- +Side-by-side model and prompt comparison out of the box
- +Includes red-teaming for injection and jailbreak testing
- +MIT, no seat limits, nothing leaves your infrastructure by default
Trade-offs
- −YAML configuration gets long on large test suites
- −Reporting UI is lighter than a hosted platform's
- −Trace history is yours to store and manage
Ragas
Strengths
- +Separates retrieval quality from generation quality
- +Can generate a synthetic test set from your own documents
- +Integrates directly with LlamaIndex and Haystack
- +Apache-2.0
Trade-offs
- −RAG-specific — not a general evaluation framework
- −Judge-model calls make large suites cost real money
- −Metric scores need calibration before you trust them
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose Promptfoo
if a lower exit cost matters more to you than any single feature, and evals live in your repo and run in CI — a regression blocks the merge.
Choose Ragas
if separates retrieval quality from generation quality.
Neither, yet
if both carry a real cost you should weigh first — yAML configuration gets long on large test suites, and rAG-specific — not a general evaluation framework. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
What it takes to run these yourself
Real requirements and honest running costs, not the vendor quickstart.
Promptfoo vs Ragas — common questions
Is Promptfoo a better fit than Ragas for llm evaluation & testing?
It depends on what you are optimising for, and the honest split is this: Promptfoo scores 94 to Ragas's 92 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. Ragas earns its place on a different axis — separates retrieval quality from generation quality. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
Promptfoo keeps its data local or in open formats, so leaving is an export rather than a negotiation. Ragas is still self-hostable, so the files stay on your server either way — but it is not local-first by design, so check what its export produces before you rely on it.
Can I self-host Promptfoo or Ragas?
Both can be self-hosted. The difference is what it costs you in time rather than whether it is possible — see the setup and maintenance rows above.
Are Promptfoo and Ragas both alternatives to Braintrust?
Yes — both appear in our Braintrust comparison, which is why they are worth putting side by side. People usually arrive here already having decided to move off Braintrust and now choosing between the two replacements, which is a narrower and much easier question.
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Facts verified 2026-08-11. Licenses and pricing change — spotted something out of date? That's a correction we want.