Inspect AI vs Promptfoo
A side-by-side comparison of Inspect AI and Promptfoo, two Eval tools, drawn from Ignaite's continuously-verified listings.
Compared from listings verified as of
At a glance
| Attribute | Inspect AI | Promptfoo |
|---|---|---|
| Category | Eval | Eval |
| Pricing | FREE | FREE |
| License | Open source | Open source |
| Deployment | — | — |
| Platforms (differs) | CLI, API | CLI, macOS, Windows, Linux |
| Model support | BYO key / model | BYO key / model |
| Vendor (differs) | UK AI Security Institute | Promptfoo |
| Capabilities (differs) |
|
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The honest brief
Inspect AI
Built by the UK AI Security Institute and adopted by Anthropic, DeepMind, METR, and Apollo as a shared eval framework; MIT.
- Adopted across major safety labs
- Composable datasets/solvers/scorers
- 200+ prebuilt evals (inspect_evals)
- Sandboxed tool + multi-turn agent runs
- MIT-licensed, provider-agnostic
- Python/code framework, not a UI product
- Steeper than no-code eval tools
- You wire up your own model keys
Promptfoo
Define evals in plain YAML and run one goldset across models in CI — a prompt regression fails the build like any other test.
- YAML-driven, version-controllable evals
- Runs in CI, model-agnostic
- Goldsets and rubric scoring
- Also does red-teaming/security scans
- CLI-first, less of a hosted UI
- Teams may want managed dashboards
- Config sprawl on large eval suites
When to pick which
Across the signals we compare, Inspect AI and Promptfoo differ on platforms:
- Platforms
- CLI, API · CLI, macOS, Windows, Linux
Their capability lists differ in recorded depth — compare the full lists above before deciding.