Confident AI (DeepEval) vs Promptfoo
Both are eval frameworks tools. Here is how they actually differ on price, billing model and deployment.
Confident AI (DeepEval)
The pytest for LLM apps - write test cases, run "deepeval test run" in CI. The OSS framework is Apache-2.0 and free; the Confident AI cloud has a steep pricing cliff from $200/mo to $2,000/mo.
Promptfoo
The de-facto open-source CLI for LLM eval and red-teaming, driven by declarative YAML. MIT-licensed, ~23.5k stars, and acquired by OpenAI in March 2026 - still open source, now part of OpenAI Frontier.
| Confident AI (DeepEval) | Promptfoo | |
|---|---|---|
| Category | Eval Frameworks | Eval Frameworks |
| Our rating | 4/5 | 4/5 |
| Starting price | $200/mo | $0 |
| Billing meter | No usage metering | No usage metering |
| Free plan | Yes | Yes |
| Free self-hosting | Yes, free | Yes, free |
| Best for | Python teams who want pytest-style LLM evals in CI/CD and can either live in the OSS framework or absorb the cloud's pricing steps | Security and CI teams who want config-driven LLM eval plus serious red-teaming, from an OSS tool with no seat cost |
Our verdict on Confident AI (DeepEval)
If your team writes Python and thinks in tests, DeepEval is the most natural eval framework there is - it really does feel like pytest for LLM apps, and the OSS core is free under Apache-2.0. The friction is the cloud. The Free tier is stingy at 5 test runs a week, and the jump from $200/mo Starter to $2,000/mo Team is a real 10x cliff. Watch the API bills too - almost every metric is LLM-as-judge.
Full Confident AI (DeepEval) review →Our verdict on Promptfoo
The clearest pick if red-teaming and security testing are part of your eval story, and its YAML-in-git approach fits CI cleanly. The OpenAI acquisition in March 2026 is the thing to weigh - the commitment to stay MIT is on the record, but you are now betting on OpenAI's stewardship of the project. For the free tier alone it is still an easy yes.
Full Promptfoo review →Frequently Asked Questions
What is the main difference between Confident AI (DeepEval) and Promptfoo?
Confident AI (DeepEval): Python teams who want pytest-style LLM evals in CI/CD and can either live in the OSS framework or absorb the cloud's pricing steps Promptfoo: Security and CI teams who want config-driven LLM eval plus serious red-teaming, from an OSS tool with no seat cost Both sit in Eval Frameworks, so the decision usually comes down to billing model and deployment rather than raw capability.
Which is cheaper, Confident AI (DeepEval) or Promptfoo?
It depends entirely on your workload shape, because they meter differently - Confident AI (DeepEval) bills on no usage metering and Promptfoo bills on no usage metering. Published starting prices are $200/mo and $0 respectively, but those numbers are not comparable until you apply them to the same traffic. Use our cost calculator to model both against your own request volume and span count.
Can I self-host Confident AI (DeepEval) or Promptfoo?
Confident AI (DeepEval): Yes, free. Promptfoo: Yes, free. Free self-hosting means no licence fee, not no cost - you still own the infrastructure, upgrades and on-call.