CORE-Bench
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.
- 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.
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:
- GPT-6 Astra
- Claude Opus 5.5
- GPT-6.1 Terra
- GPT-6.1 Sol
- and 16 more
- 77.8 Claude Opus 4.5
- 62.2 Claude Sonnet 4.5
- 51.1 Claude Opus 4.1
- 46.7 Claude Sonnet 4
- 40.0
Gemini 3 Pro
- 37.8 Claude 3.7 Sonnet
- 35.6 o4-mini
- 33.3 GPT-4.1
- 26.7 GPT-5
- 24.4 o3
- 22.2
Gemini 2.5 Pro
- 20.0
DeepSeek-V3.1
- 17.8
DeepSeek-V3
- 11.1
Gemini 2.0 Flash
- 11.1 gpt-oss-120b
- 11.1 Claude Haiku 4.5
- 8.89
DeepSeek-R1
- 1 Claude Opus 4.5 77.8%
- 2 Claude Sonnet 4.5 62.2%
- 3 Claude Opus 4.1 51.1%
- 4 Claude Sonnet 4 46.7%
- 5
Gemini 3 Pro high 40%
- 6 Claude 3.7 Sonnet high 37.8%
- 7 o4-mini high 35.6%
- 8 GPT-4.1 33.3%
- 9 GPT-5 medium 26.7%
- 10 o3 medium 24.4%
- 11
Gemini 2.5 Pro Jun 2025 22.2%
- 12
DeepSeek-V3.1 20%
- 13
DeepSeek-V3 Mar 2025 17.8%
- 14
Gemini 2.0 Flash Feb 2025 11.1%
- 15 gpt-oss-120b 11.1%
- 16 Claude Haiku 4.5 11.1%
- 17
DeepSeek-R1 May 2025 8.89%
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 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 | | 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 | | 22.2% | CORE-Agent | Jun 2025 | Official leaderboard |
| 12 | | 20% | CORE-Agent | Aug 2025 | Official leaderboard |
| 13 | | 17.8% | CORE-Agent | Mar 2025 | Official leaderboard |
| 14 | | 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 | | 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.
| Model | Effort | Harness | Score | Cost per task | Output 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% | |||
| | 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% | |||
| | 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% | ||
| | CORE-Agent | 22.2% | |||
| | CORE-Agent | 20% | |||
| | CORE-Agent | 17.8% | |||
| o4-mini | low | CORE-Agent | 17.8% | ||
| o4-mini | low | HAL Generalist Agent | 15.6% | ||
| | 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% | |||
| | HAL Generalist Agent | 8.89% | |||
| | HAL Generalist Agent | 8.89% | |||
| gpt-oss-120b | high | HAL Generalist Agent | 8.89% | ||
| gpt-oss-120b | HAL Generalist Agent | 8.89% | |||
| | CORE-Agent | 6.67% | |||
| | HAL Generalist Agent | 4.45% | |||
| | HAL Generalist Agent | 4.44% | |||
| | 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.
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
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.
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