Benchmark Almanac

CORE-Bench

Claude Opus 4.5 77.8% leads since Nov 2025 Not in model cards

Agents reproduce the results of published studies from their code and data. 270 tasks from 90 papers in computer science, social science and medicine come in three difficulty levels.

CORE-Bench Hard is the level most often reported. Princeton's Holistic Agent Leaderboard runs it.

In the authors’ words

AI agents have the potential to aid users on a variety of consequential tasks, including conducting scientific research. To spur the development of useful agents, we need benchmarks that are challenging, but more crucially, directly correspond to real-world tasks of interest. This paper introduces such a benchmark, designed to measure the accuracy of AI agents in tackling a crucial yet surprisingly challenging aspect of scientific research: computational reproducibility. This task, fundamental to the scientific process, involves reproducing the results of a study using the provided code and data. We introduce CORE-Bench (Computational Reproducibility Agent Benchmark), a benchmark consisting of 270 tasks based on 90 scientific papers across three disciplines (computer science, social science, and medicine). Tasks in CORE-Bench consist of three difficulty levels and include both language-only and vision-language tasks. We provide an evaluation system to measure the accuracy of agents in a fast and parallelizable way, saving days of evaluation time for each run compared to a sequential implementation. We evaluated two baseline agents: the general-purpose AutoGPT and a task-specific agent called CORE-Agent. We tested both variants using two underlying language models: GPT-4o and GPT-4o-mini. The best agent achieved an accuracy of 21% on the hardest task, showing the vast scope for improvement in automating routine scientific tasks. Having agents that can reproduce existing work is a necessary step towards building agents that can conduct novel research and could verify and improve the performance of other research agents. We hope that CORE-Bench can improve the state of reproducibility and spur the development of future research agents.

Abstract of CORE-Bench: Fostering the Credibility of Published Research Through a Computational Reproducibility Agent Benchmark (arXiv:2409.11363, CC0)
Made by Princeton University Released Sep 2024 Research science All tasks public Last model added Nov 2025 Scores refreshed 2 Nov 2026
Level
Expert Specialists with years of training, often over hours of work
Scored
Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
Answers
Agent task Many steps in a terminal, browser, desktop, app, game or robot.
17
Models scored on its own leaderboard

Claude Opus 4.5 leads with 77.8% among models released by Nov 2025

Best score per model from the benchmark's own leaderboard, read on 2 Nov 2026. Where a model ran with several settings or harnesses, we keep its best. Every run is in the next chart.

The newest model with a score here came out in Nov 2025, 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 Opus 4.5 77.8%
  2. 2 Claude Sonnet 4.5 62.2%
  3. 3 Claude Opus 4.1 51.1%
  4. 4 Claude Sonnet 4 46.7%
  5. 5 Gemini 3 Pro high 40%
  6. 6 Claude 3.7 Sonnet high 37.8%
  7. 7 o4-mini high 35.6%
  8. 8 GPT-4.1 33.3%
  9. 9 GPT-5 medium 26.7%
  10. 10 o3 medium 24.4%
  11. 11 Gemini 2.5 Pro Jun 2025 22.2%
  12. 12 DeepSeek-V3.1 20%
  13. 13 DeepSeek-V3 Mar 2025 17.8%
  14. 14 Gemini 2.0 Flash Feb 2025 11.1%
  15. 15 gpt-oss-120b 11.1%
  16. 16 Claude Haiku 4.5 11.1%
  17. 17 DeepSeek-R1 May 2025 8.89%
#ModelScoreSettingDateSource
1 Claude Opus 4.5 77.8% Claude Code Nov 2025 Official leaderboard
2 Claude Sonnet 4.5 62.2% Claude Code Sep 2025 Official leaderboard
3 Claude Opus 4.1 51.1% CORE-Agent Aug 2025 Official leaderboard
4 Claude Sonnet 4 46.7% Claude Code May 2025 Official leaderboard
5 Gemini 3 Pro 40% high, CORE-Agent Nov 2025 Official leaderboard
6 Claude 3.7 Sonnet 37.8% high, HAL Generalist Agent Feb 2025 Official leaderboard
7 o4-mini 35.6% high, HAL Generalist Agent Apr 2025 Official leaderboard
8 GPT-4.1 33.3% CORE-Agent Apr 2025 Official leaderboard
9 GPT-5 26.7% medium, CORE-Agent Aug 2025 Official leaderboard
10 o3 24.4% medium, CORE-Agent Apr 2025 Official leaderboard
11 Gemini 2.5 Pro Jun 2025 22.2% CORE-Agent Jun 2025 Official leaderboard
12 DeepSeek-V3.1 20% CORE-Agent Aug 2025 Official leaderboard
13 DeepSeek-V3 Mar 2025 17.8% CORE-Agent Mar 2025 Official leaderboard
14 Gemini 2.0 Flash Feb 2025 11.1% CORE-Agent Feb 2025 Official leaderboard
15 gpt-oss-120b 11.1% CORE-Agent Aug 2025 Official leaderboard
16 Claude Haiku 4.5 11.1% CORE-Agent Oct 2025 Official leaderboard
17 DeepSeek-R1 May 2025 8.89% HAL Generalist Agent May 2025 Official leaderboard

More effort adds a median 20 points

Models the leaderboard ran at two or more effort levels. We don’t have enough cost data here to say what the extra effort costs.

Lowest effort to highest, light to dark
Claude Opus 4.1 CORE-Agent
high
51.1%
Claude Sonnet 4.5 CORE-Agent
high
44.4%
Claude Opus 4.5 CORE-Agent
high
42.2%
Claude 3.7 Sonnet HAL Generalist Agent
high
37.8%
Claude 3.7 Sonnet CORE-Agent
high
35.6%
o4-mini HAL Generalist Agent
low high
35.6%
Claude Opus 4.1 HAL Generalist Agent
high
35.6%
Claude Sonnet 4 CORE-Agent
high
33.3%
Claude Sonnet 4.5 HAL Generalist Agent
high
33.3%
Claude Opus 4.5 HAL Generalist Agent
high
33.3%
o4-mini CORE-Agent
low high
26.7%
gpt-oss-120b CORE-Agent
high
11.1%
ModelEffortHarnessScoreCost per taskOutput tokens
Claude Opus 4.5 Claude Code 77.8%
Claude Sonnet 4.5 Claude Code 62.2%
Claude Opus 4.1 CORE-Agent 51.1%
Claude Sonnet 4 Claude Code 46.7%
Claude Sonnet 4.5 high CORE-Agent 44.4%
Claude Opus 4.1 Claude Code 42.2%
Claude Opus 4.1 high CORE-Agent 42.2%
Claude Opus 4.5 high CORE-Agent 42.2%
Claude Opus 4.5 CORE-Agent 42.2%
Gemini 3 Pro high CORE-Agent 40%
Claude 3.7 Sonnet high HAL Generalist Agent 37.8%
Claude Sonnet 4.5 CORE-Agent 37.8%
Claude 3.7 Sonnet CORE-Agent 35.6%
o4-mini high HAL Generalist Agent 35.6%
Claude Opus 4.1 HAL Generalist Agent 35.6%
Gemini 3 Pro high HAL Generalist Agent 35.6%
GPT-4.1 CORE-Agent 33.3%
Claude Sonnet 4 high CORE-Agent 33.3%
Claude Opus 4.1 high HAL Generalist Agent 33.3%
Claude Sonnet 4.5 HAL Generalist Agent 33.3%
Claude Opus 4.5 HAL Generalist Agent 33.3%
Claude 3.7 Sonnet HAL Generalist Agent 31.1%
Claude Opus 4.5 high HAL Generalist Agent 31.1%
Claude Sonnet 4 CORE-Agent 28.9%
Claude Sonnet 4.5 high HAL Generalist Agent 28.9%
o4-mini high CORE-Agent 26.7%
GPT-5 medium CORE-Agent 26.7%
Claude 3.7 Sonnet high CORE-Agent 24.4%
o3 medium CORE-Agent 24.4%
GPT-4.1 HAL Generalist Agent 22.2%
o3 medium HAL Generalist Agent 22.2%
Gemini 2.5 Pro Jun 2025 CORE-Agent 22.2%
DeepSeek-V3.1 CORE-Agent 20%
DeepSeek-V3 Mar 2025 CORE-Agent 17.8%
o4-mini low CORE-Agent 17.8%
o4-mini low HAL Generalist Agent 15.6%
Gemini 2.0 Flash Feb 2025 CORE-Agent 11.1%
gpt-oss-120b CORE-Agent 11.1%
gpt-oss-120b high CORE-Agent 11.1%
GPT-5 medium HAL Generalist Agent 11.1%
Claude Haiku 4.5 CORE-Agent 11.1%
DeepSeek-V3 Mar 2025 HAL Generalist Agent 8.89%
DeepSeek-R1 May 2025 HAL Generalist Agent 8.89%
gpt-oss-120b high HAL Generalist Agent 8.89%
gpt-oss-120b HAL Generalist Agent 8.89%
DeepSeek-R1 May 2025 CORE-Agent 6.67%
DeepSeek-R1 May 2025 HAL Generalist Agent 4.45%
Gemini 2.0 Flash Feb 2025 HAL Generalist Agent 4.44%
Gemini 2.5 Pro Jun 2025 HAL Generalist Agent 4.44%

6 models have held number one since its release in Sep 2024

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

Google DeepMind Anthropic
Own leaderboard Not tested since Nov 2025

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 Best so far
0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) Claude Opus 4.5 Claude Sonnet 4.5 Claude Opus 4.1 Claude Sonnet 4 Claude 3.7 Sonnet Gemini 2.0 Flash 0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) Claude Opus 4.5 Claude Sonnet 4.5

No lab model card reports it yet

We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark.

More in Science and reasoning

All 88 in Science and reasoning
  • GPQA Diamond In use 198 graduate-level 'Google-proof' multiple-choice questions in biology, chemistry and physics. Gemini 4 Argon 96.4%
  • Terminal-Bench-Science In use 70 scientific research-workflow tasks across five science areas, run in Harbor containers. Hidden tests give the resolution rate. GPT-6 Astra 68.1%
  • 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 Opus 5 90.1%
  • 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%