Inspect AI vs DeepEval
Both are alternatives to Braintrust. Here's how they stack up — verified facts, no spin.
Also searched as DeepEval vs Inspect AI — same comparison, one verdict.
Inspect AI and DeepEval are closely matched on ownership (93 vs 92) — this one comes down to pricing and to which trade-offs below you can live with.
Inspect AI
The rigorous one, from the UK AI Safety Institute.
Inspect is the evaluation framework built by the UK AI Safety Institute for evaluating frontier models, released MIT. It is the most methodologically serious option here: first-class support for multi-turn agent evaluations, tool use, sandboxed execution and human grading, with a design that takes statistical validity seriously rather than producing a number that feels reassuring. If your evaluations need to withstand scrutiny — regulatory, academic or internal — this is the one.
DeepEval
Evals as pytest tests, with the research metrics already implemented.
DeepEval brings LLM evaluation into pytest, so an eval is a test function and your existing test runner, CI integration and reporting all work unchanged. It ships implementations of the metrics people actually cite — answer relevancy, faithfulness, contextual precision and recall, hallucination, bias, toxicity — including several LLM-as-judge metrics done carefully. Apache-2.0, from Confident AI, who sell an optional hosted platform.
Side by side
6 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.
| Inspect AI | DeepEval | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 93 | 92 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first data | Yes | Yes |
| License | MIT | Apache-2.0 |
| Pricing | Free, MIT, publicly funded. | Free and Apache-2.0; optional paid cloud dashboard. |
Inspect AI edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Weighing both against staying on Braintrust? Is Braintrust free? What it actually costs →
Inspect AI
Strengths
- +Built for evaluations that have to survive real scrutiny
- +Strong agent, tool-use and sandboxed-execution support
- +Excellent log viewer for inspecting individual samples
- +MIT, from a public institute with no commercial upsell
Trade-offs
- −Aimed at model evaluation more than application regression testing
- −Steeper learning curve than Promptfoo for simple cases
- −Less oriented toward CI gating out of the box
DeepEval
Strengths
- +Pytest-native — your existing CI and reporting just work
- +Large library of implemented, research-backed metrics
- +Synthetic test-case generation for cold-start coverage
- +Apache-2.0 with no seat cost
Trade-offs
- −LLM-as-judge metrics cost tokens on every run
- −Assumes a Python codebase
- −Best dashboard experience is the paid hosted one
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose Inspect AI
if a lower exit cost matters more to you than any single feature, and built for evaluations that have to survive real scrutiny.
Choose DeepEval
if pytest-native — your existing CI and reporting just work.
Neither, yet
if both carry a real cost you should weigh first — aimed at model evaluation more than application regression testing, and lLM-as-judge metrics cost tokens on every run. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
Inspect AI vs DeepEval — common questions
Is Inspect AI a better fit than DeepEval for llm evaluation & testing?
It depends on what you are optimising for, and the honest split is this: Inspect AI scores 93 to DeepEval's 92 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. DeepEval earns its place on a different axis — pytest-native — your existing CI and reporting just work. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
Inspect AI keeps its data local or in open formats, so leaving is an export rather than a negotiation. DeepEval 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 Inspect AI or DeepEval?
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 Inspect AI and DeepEval 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.