Benchmark Almanac

PaperBench

Qwen 3.8 Max 93% leads since Aug 2026 In use

Agent replicates ICML 2024 papers from scratch. LLM judge grades against author-written hierarchical rubrics.

Repo renamed from openai/preparedness. Qwen and MiniMax use different judges (Opus 4.6) and 12h runs, so scores are not comparable.

In the authors’ words

We introduce PaperBench, a benchmark evaluating the ability of AI agents to replicate state-of-the-art AI research. Agents must replicate 20 ICML 2024 Spotlight and Oral papers from scratch, including understanding paper contributions, developing a codebase, and successfully executing experiments. For objective evaluation, we develop rubrics that hierarchically decompose each replication task into smaller sub-tasks with clear grading criteria. In total, PaperBench contains 8,316 individually gradable tasks. Rubrics are co-developed with the author(s) of each ICML paper for accuracy and realism. To enable scalable evaluation, we also develop an LLM-based judge to automatically grade replication attempts against rubrics, and assess our judge's performance by creating a separate benchmark for judges. We evaluate several frontier models on PaperBench, finding that the best-performing tested agent, Claude 3.5 Sonnet (New) with open-source scaffolding, achieves an average replication score of 21.0%. Finally, we recruit top ML PhDs to attempt a subset of PaperBench, finding that models do not yet outperform the human baseline. We open-source our code (https://github.com/openai/preparedness) to facilitate future research in understanding the AI engineering capabilities of AI agents.

Abstract of PaperBench: Evaluating AI's Ability to Replicate AI Research (arXiv:2504.01848, CC0)
Made by OpenAI Released Apr 2025 AI research tasks All tasks public Last in a launch post Aug 2026 Last model added Aug 2026
Level
Research frontier Researchers, on open problems or tasks that take days
Scored
Graded by a model A language model scores each response, usually against a rubric.
Answers
Agent task Many steps in a terminal, browser, desktop, app, game or robot.
14
Models scored in lab cards
4
Launch posts list it, from 4 labs
12
System cards report it, from 2 labs

Qwen 3.8 Max leads with 93% among models released by Aug 2026

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

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

  1. 1 Qwen 3.8 Max 93%
  2. 2 Kimi K2.5 63.5%
  3. 3 MiniMax-M3 52.6%
  4. 4 Seed2.0 Lite (0428) 52.5%
  5. 5 GPT-5.2 Codex 43%
  6. 6 GPT-5.1-Codex-Max 40%
  7. 7 GPT-5.2 39%
  8. 8 Kimi K2 Jul 2025 27.8%
  9. 9 o4-mini 25%
  10. 10 GPT-5 24%
  11. 11 GPT-5 mini 23%
  12. 12 o3 18%
  13. 13 gpt-oss-120b 11%
  14. 14 gpt-oss-20b 7.00%
#ModelScoreSettingDateSource
1 Qwen 3.8 Max 93% Aug 2026 Model card
2 Kimi K2.5 63.5% Jan 2026 Model card
3 MiniMax-M3 52.6% Jun 2026 Model card
4 Seed2.0 Lite (0428) 52.5% Apr 2026 Model card
5 GPT-5.2 Codex 43% Dec 2025 Model card
6 GPT-5.1-Codex-Max 40% Nov 2025 Model card
7 GPT-5.2 39% Dec 2025 Model card
8 Kimi K2 Jul 2025 27.8% Jul 2025 Model card
9 o4-mini 25% Apr 2025 Model card
10 GPT-5 24% Aug 2025 Model card
11 GPT-5 mini 23% Aug 2025 Model card
12 o3 18% Apr 2025 Model card
13 gpt-oss-120b 11% Aug 2025 Model card
14 gpt-oss-20b 7.00% Aug 2025 Model card

6 models have held number one since its release in Apr 2025

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

OpenAI Moonshot AI Qwen
Lab claims Passed 85% in Aug 2026, by Qwen 3.8 Max

The best score passed 85% in Aug 2026

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

Reported by the lab in its model card Best so far
0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) Qwen 3.8 Max Kimi K2.5 GPT-5.2 Codex Kimi K2 0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) Qwen 3.8 Max Kimi K2.5

2 labs put it in a launch post in the last six months

Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.

Moonshot AI
ByteDance Seed
MiniMax
Qwen
DateLaunch postScoreAs the post writes it
3 Aug 2026 Qwen 3.8 Max 93 PaperBench
1 Jun 2026 MiniMax-M3 52.6 PaperBench
28 Apr 2026 Seed2.0 Lite (0428) 52.5 PaperBench
27 Jan 2026 Kimi K2.5 63.5 PaperBench

12 system cards report it, from 2 labs

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.

DateDocumentScoreAs the document writes itSection
30 Jan 2026 Kimi K2.5 technical report 63.5 PaperBench (CodeDev) (Table 4) AI R&D risk
18 Dec 2025 GPT-5.2 Codex system card addendum 43 PaperBench (no browsing), 10-paper subset, pass@1, Extra High reasoning effort, printed chart label (Figure 11, 5.1.3.3) AI R&D risk
11 Dec 2025 GPT-5.2 system card addendum 39 PaperBench (no browsing), 10-paper subset, pass@1, high reasoning effort, printed chart label (Figure 15) AI R&D risk
18 Nov 2025 GPT-5.1-Codex-Max system card 40 PaperBench (no browsing), 10-paper subset, pass@1, Extra High reasoning effort, printed chart label (Figure 9, 5.1.3.2) AI R&D risk
7 Aug 2025 GPT-5 system card 24 PaperBench 10-paper subset (no browsing), pass@1, launch candidate (Figure 25) AI R&D risk
7 Aug 2025 GPT-5 mini system card 23 PaperBench 10-paper subset (no browsing), pass@1, gpt-5-thinking-mini launch candidate (Figure 25) AI R&D risk
5 Aug 2025 gpt-oss-20b model card 7 PaperBench 10-paper subset (no browsing), pass@1, gpt-oss 20b launch candidate (Figure 16) AI R&D risk
5 Aug 2025 gpt-oss-120b model card 11 PaperBench 10-paper subset (no browsing), pass@1, gpt-oss 120b launch candidate (Figure 16) AI R&D risk
21 Jul 2025 Kimi K2 technical report 27.8 Paper Bench Code-Dev (Acc.) (Table 3) AI R&D risk
17 Jul 2025 ChatGPT agent system card PaperBench (no browsing), 10-paper subset, pass@1, chart shows only ChatGPT Agent no-browsing helpful-only at 22%, no released-model value (Figure 18, 5.1.3.4) AI R&D risk
16 Apr 2025 o4-mini system card 25 PaperBench (no browsing), pass@1, high reasoning effort, o4-mini no browsing launch candidate, printed chart label (Figure 23), text says 24% AI R&D risk
16 Apr 2025 o3 system card 18 PaperBench (no browsing), pass@1, high reasoning effort, o3 no browsing launch candidate, printed chart label (Figure 23) AI R&D risk

More in AI research

All 83 in AI research
  • MLS-Bench In use Agent must invent one algorithmic change in an ML research scaffold whose gain transfers across settings. Scored relative to human baselines. Claude Fable 5.1 50.3%
  • MLE-bench In use Kaggle-style ML engineering competitions. Agent trains models and is scored against competition leaderboards. GPT-6 Astra 93.8%
  • PostTrainBench 1.2 In use CLI agent gets a base model, one H100 and a time budget to post-train it for a target benchmark. Scored on normalized gain. Claude Fable 5.1 44.6%
  • KernelBench In use Replace PyTorch operators with faster custom GPU kernels. Scored on correctness and speedup. MiniMax-M3 28.8%
  • OpenAI PRs Only in system cards Agents replicate internal OpenAI pull requests from a pre-PR branch and a prompt. Graded by hidden unit tests as pass@1. GPT-5.2 55%
  • OpenAI Research Engineer Interview: Multiple Choice Only in system cards Models answer 97 multiple-choice questions drawn from OpenAI machine learning interview topics. Scored as cons@32. o4-mini 83%