Benchmark Almanac

EurekaBench

Claude Fable 5.1 29.8 leads since September 2026
Not in model cards

Agents run long experiments and propose mechanisms that explain observations in six sciences. Mechanisms are scored on known constraints, predictive accuracy and the 306 expert-listed insights they should support.

26 expert-verified tasks across neuroscience, computer science, chemistry, astrophysics, geophysics and plasma physics. Grading of insights is assumed model-judged and should be checked. Repo has 35 stars.

Released
September 2026
Kind
Research science
Level
Research frontier
Scored
Graded by a model
Answers
Agent task
Tasks
All public
Strongest model tested
GPT-6 Astra #3 on the capability index
Last model added
September 2026
Scores refreshed
November 12th, 2026

In the authors’ words

When Isaac Newton discovered the law of gravitation, he did so through an iterative process of analyzing observed data such as planetary patterns, finding the underlying mechanisms by describing patterns in mathematical equations, and refining his theory against the Moon's orbit, revealing the startling insight that the same force governs both falling apples and orbiting planets. Would it be possible for AI agents to make similar discoveries? To measure this ability, we introduce EurekaBench, a cross-domain benchmark that tests AI agents' ability to conduct long-horizon experiments and discover mechanisms that explain observations. We evaluate these mechanisms by the scientific insights that can be derived from them. EurekaBench contains an expert-verified set of 26 long-horizon tasks across neuroscience, computer science, chemistry, astrophysics, geophysics, and plasma physics, with a total of 306 scientific insights that the discovered mechanisms are expected to support. Our evaluation framework tests three axes of scientific discovery: agents' ability to follow known scientific constraints, the predictive accuracy of the discovered mechanisms, and whether these mechanisms yield scientific insights or inform future research. Our results show that current AI agents often overly fixate on predictive accuracy optimization, surpassing human scientists, while falling substantially short in deriving scientific insights.

Abstract of EurekaBench: Measuring Agentic Ability to Discover New Scientific Insights (arXiv:2610.00492, CC0)
7
Models scored on its own leaderboard

Claude Fable 5.1 leads with 29.8 among models released by September 2026

Best score per model from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best.

The newest model with a score here came out in September 2026, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 1 Claude Fable 5.1 xhigh 29.8
  2. 2 GPT-6 Astra xhigh 28.7
  3. 3 Claude Opus 5 xhigh 27.3
  4. 4 GPT-5.6 Sol xhigh 19.4
  5. 5 Claude Opus 4.8 xhigh 18.4
  6. 6 DeepSeek-V4-Flash xhigh 14.6
  7. 7 Kimi K3 xhigh 12.9

Source: Official EurekaBench leaderboard

#ModelScoreSettingDateSource
1 Claude Fable 5.1 29.8 xhigh, Claude Code Sep 2026 Official leaderboard
2 GPT-6 Astra 28.7 xhigh, Codex Sep 2026 Official leaderboard
3 Claude Opus 5 27.3 xhigh, Claude Code Jul 2026 Official leaderboard
4 GPT-5.6 Sol 19.4 xhigh, Codex Jul 2026 Official leaderboard
5 Claude Opus 4.8 18.4 xhigh, Claude Code May 2026 Official leaderboard
6 DeepSeek-V4-Flash 14.6 xhigh, OpenHands Apr 2026 Official leaderboard
7 Kimi K3 12.9 xhigh, OpenHands Jul 2026 Official leaderboard

Number one over time

Lab claims count from the day the card came out, independent runs from the model’s release.

Anthropic
Own leaderboard Not tested since Sep 2026

Source: Official EurekaBench leaderboard

Scores over time

All the scores we have, one dot each, so a model tested at several settings appears more than once.

On the benchmark’s own leaderboard
10.0 15.0 20.0 25.0 30.0 2026 10.0 15.0 20.0 25.0 30.0 2026

Source: Official EurekaBench leaderboard

No lab model card reports it yet

We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark.

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  • FrontierScience In use Models solve physics, chemistry, and biology problems in an Olympiad track graded by short answer and a Research track graded by 10-point rubrics. Intern-S2-397B 87%
  • BioMysteryBench In use Bioinformatics problems on anonymized real datasets that require real analysis with tools. Rubric-graded, with human-solvable and human-difficult splits. Claude Fable 5.2 83.7%
  • HiPhO In use Models solve theory problems from 2024 and 2025 physics olympiad exams, some with diagrams. Official marking schemes grade answers and steps, mapped to medal levels. Gemini 3 Pro 78.3%
  • LABBench2 In use 11 biology research sub-tasks (literature, figures, tables, patents, trials and more) with tool access. Macro-averaged accuracy. GPT-5.2 60.9%