Promptfoo vs Openlayer
Both are eval frameworks tools. Here is how they actually differ on price, billing model and deployment.
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.
Openlayer
A commercial LLM and ML evaluation platform with 100+ built-in tests and, unusually, explicit alignment to the EU AI Act and NIST frameworks. Pricing is entirely sales-led with nothing published.
| Promptfoo | Openlayer | |
|---|---|---|
| Category | Eval Frameworks | Eval Frameworks |
| Our rating | 4/5 | 3/5 |
| Starting price | $0 | Not published |
| Billing meter | No usage metering | No usage metering |
| Free plan | Yes | No |
| Free self-hosting | Yes, free | No or paid tier only |
| Best for | Security and CI teams who want config-driven LLM eval plus serious red-teaming, from an OSS tool with no seat cost | Regulated enterprises that need evaluation with documented EU AI Act or NIST alignment, and teams evaluating both classical ML and LLM systems who want one platform and can work with enterprise procurement. |
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 →Our verdict on Openlayer
Openlayer is a competent commercial evaluation platform whose most interesting feature is compliance rather than capability. The test library is substantial at 100+ built-in and customisable tests, agent evaluation extends properly into tool call correctness and reasoning trace review rather than stopping at output scoring, and CI/CD validation is treated as a first-class workflow. But the thing that differentiates it is explicit alignment to the EU AI Act and NIST frameworks, which is rare in this category and is rapidly moving from a nicety to a procurement requirement for anyone deploying AI in Europe or into US government-adjacent markets. The problem is access. There is no published pricing of any kind and no free tier, so unlike almost every competitor you cannot try it or cost it without entering a sales process. For an enterprise with a procurement function that is normal. For everyone else it is a wall, and it means Openlayer will be eliminated from most shortlists before its actual merits are assessed.
Full Openlayer review →Frequently Asked Questions
What is the main difference between Promptfoo and Openlayer?
Promptfoo: Security and CI teams who want config-driven LLM eval plus serious red-teaming, from an OSS tool with no seat cost Openlayer: Regulated enterprises that need evaluation with documented EU AI Act or NIST alignment, and teams evaluating both classical ML and LLM systems who want one platform and can work with enterprise procurement. Both sit in Eval Frameworks, so the decision usually comes down to billing model and deployment rather than raw capability.
Which is cheaper, Promptfoo or Openlayer?
It depends entirely on your workload shape, because they meter differently - Promptfoo bills on no usage metering and Openlayer bills on no usage metering. Published starting prices are $0 and Not published 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 Promptfoo or Openlayer?
Promptfoo: Yes, free. Openlayer: No or paid tier only. Free self-hosting means no licence fee, not no cost - you still own the infrastructure, upgrades and on-call.