Input hallucinations (Anthropic)
Only in system cards
Models answer 500 prompts that need an unavailable tool and 500 prompts that cite missing context. Score is the non-hallucination rate.
In-house Anthropic evaluation. Reported as two sets with no overall score.
Made by Anthropic Released Apr 2026 Hallucination rates Tasks kept private Last in a system card Apr 2026
Last model added Apr 2026
- Level
- Everyday Most adults, without training
- Scored
- Graded by a model A language model scores each response, usually against a rubric.
- Answers
- Open-ended Free-form text, documents, designs or media judged as a whole.
2
System cards report it, from 1 lab
No scores here yet
No lab, leaderboard or Epoch AI run has reported a score for Input hallucinations (Anthropic) yet.
Labs report it only in system cards
We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark. Some system cards do, below.
2 system cards report it, from 1 lab
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| 16 Apr 2026 | Claude Opus 4.7 system card | Input hallucinations, non-hallucination rate, no overall: capability set 89.5, missing-context set 91.8, printed on chart (6.3.3.4, Figure 6.3.3.4.A) | Hallucination | |
| 7 Apr 2026 | Claude Mythos Preview system card | Input hallucinations, non-hallucination rate, missing tools 84.8 and missing context 93.8, no overall, values printed on chart (4.3.3.5, Figure 4.3.3.5.A) | Hallucination |
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