# LLM and agent evaluation tools — The Agents Index

> Source: https://theagentsindex.com/category/llm-evaluation (curated, re-verified)
> Updated 31 October 2026 · Reviewed by The Agents Index editorial team

Test sets, scorers and judges that measure whether a model or an agent got it right.

1 agent in this category, A to Z. Each name links to its answer-first markdown twin.

## Facts

- Free to start: 1 of 1
- API: 0 of 1
- First paid plan a month: none of the 1 publishes one
- Checked against their own sites: 29 October 2026 (1 of 1)
- Added in November 2026: 0

| Name | What it is | Pricing |
| --- | --- | --- |
| [Promptfoo](https://theagentsindex.com/promptfoo.md) | Open-source LLM evaluation and red-team testing that can run locally or self-hosted. | Free |

## LLM and agent evaluation tools compared

| Agent | Vendor's price | MCP server | API | Open source | Self-host |
| --- | --- | --- | --- | --- | --- |
| [Promptfoo](https://theagentsindex.com/promptfoo) | Free | Not stated | Not stated | Yes | Yes |

All 1 LLM and agent evaluation tools we list.

## Questions buyers ask

### Which tool here costs the least?

Promptfoo has a free plan.

### When were these prices checked?

On 29 October 2026, each read on the maker's own pricing page.

## Sources and method

Listed A to Z. [How we check](https://theagentsindex.com/methodology/)

Every price here was read on the maker's own pricing page.

- [Promptfoo](https://theagentsindex.com/promptfoo): [promptfoo.dev/pricing](https://www.promptfoo.dev/pricing), checked 29 October 2026