Benchmark Almanac

PaperBench

Qwen 3.8 Max 93% leads since August 2026
o1 26% leads since April 2025
Qwen 3.8 Max 93% leads since August 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.

Made by
OpenAI
Released
April 2025
Kind
AI research tasks
Level
Research frontier
Scored
Graded by a model
Answers
Agent task
Tasks
All public
Strongest model tested
Qwen 3.8 Max #29 on the capability index
Last in a launch post
November 2026
Last model added
November 2026
Scores refreshed
November 12th, 2026

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)
15
Models scored in lab cards
5
Launch posts list it, from 5 labs
12
System cards report it, from 2 labs

Qwen 3.8 Max leads with 93%

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.

o1 leads with 26% across all independent runs

Best score per model across the official leaderboard, Epoch AI’s own runs and any board Epoch AI copied. Each bar and row names its source.

Qwen 3.8 Max leads with 93%, claims included

Best score per model from every source, including labs’ own numbers and claims Epoch AI collected from reports and papers. Labs pick their own settings, so a claim can beat an independent run of the same model.

  1. 1 Qwen 3.8 Max 93%
  2. 2 LongCat-2.5 82.1%
  3. 3 Kimi K2.5 63.5%
  4. 4 MiniMax-M3 52.6%
  5. 5 Seed2.0 Lite (0428) 52.5%
  6. 6 GPT-5.2 Codex 43%
  7. 7 GPT-5.1-Codex-Max 40%
  8. 8 GPT-5.2 39%
  9. 9 Kimi K2 Jul 2025 27.8%
  10. 10 o4-mini 25%
  11. 11 GPT-5 24%
  12. 12 GPT-5 mini 23%
  13. 13 o3 18%
  14. 14 gpt-oss-120b 11%
  15. 15 gpt-oss-20b 7.00%

Source: Labs’ model cards

#ModelScoreSettingDateSource
1 Qwen 3.8 Max 93% Aug 2026 Lab model card
2 LongCat-2.5 82.1% Nov 2026 Lab model card
3 Kimi K2.5 63.5% Jan 2026 Lab model card
4 MiniMax-M3 52.6% Jun 2026 Lab model card
5 Seed2.0 Lite (0428) 52.5% Apr 2026 Lab model card
6 GPT-5.2 Codex 43% Dec 2025 Lab model card
7 GPT-5.1-Codex-Max 40% Nov 2025 Lab model card
8 GPT-5.2 39% Dec 2025 Lab model card
9 Kimi K2 Jul 2025 27.8% Jul 2025 Lab model card
10 o4-mini 25% Apr 2025 Lab model card
11 GPT-5 24% Aug 2025 Lab model card
12 GPT-5 mini 23% Aug 2025 Lab model card
13 o3 18% Apr 2025 Lab model card
14 gpt-oss-120b 11% Aug 2025 Lab model card
15 gpt-oss-20b 7.00% Aug 2025 Lab model card
#ModelScoreSettingDateSource
1 o1 26% PaperBench; high; 36h limit, IterativeAgent Dec 2024 Official leaderboard
2 o3-mini 8.50% PaperBench; high, IterativeAgent Jan 2025 Official leaderboard
3 DeepSeek-R1 6.00% PaperBench, BasicAgent Jan 2025 Official leaderboard
#ModelScoreSettingDateSource
1 Qwen 3.8 Max 93% Aug 2026 Lab model card
2 LongCat-2.5 82.1% Nov 2026 Lab model card
3 Kimi K2.5 63.5% Jan 2026 Lab model card
4 MiniMax-M3 52.6% Jun 2026 Lab model card
5 Seed2.0 Lite (0428) 52.5% Apr 2026 Lab model card
6 GPT-5.2 Codex 43% Dec 2025 Lab model card
7 GPT-5.1-Codex-Max 40% Nov 2025 Lab model card
8 GPT-5.2 39% Dec 2025 Lab model card
9 Kimi K2 Jul 2025 27.8% Jul 2025 Lab model card
10 o1 26% PaperBench; high; 36h limit, IterativeAgent Dec 2024 Official leaderboard
11 o4-mini 25% Apr 2025 Lab model card
12 GPT-5 24% Aug 2025 Lab model card
13 GPT-5 mini 23% Aug 2025 Lab model card
14 o3 18% Apr 2025 Lab model card
15 gpt-oss-120b 11% Aug 2025 Lab model card
16 o3-mini 8.50% PaperBench; high, IterativeAgent Jan 2025 Official leaderboard
17 gpt-oss-20b 7.00% Aug 2025 Lab model card
18 DeepSeek-R1 6.00% PaperBench, BasicAgent Jan 2025 Official leaderboard

The benchmark's own leaderboard has 6 entries, 3 of them models we track. Switch the scores above to rank them together.

6 models have held number one in labs’ own numbers since its release in April 2025 Number one over time 6 models have held number one with claims included since its release in April 2025

Lab claims count from the day the card came out, independent runs from the model’s release. We draw one row each for the benchmark’s own leaderboard and what labs claim in their cards.

OpenAI Moonshot AI Qwen
Own leaderboard Not tested since Apr 2025
o1 26%
Lab claims Passed 85% in Aug 2026, by Qwen 3.8 Max

Sources: Official PaperBench leaderboard and labs’ model cards

Qwen’s own number for Qwen 3.8 Max passed 85% in August 2026

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 Reported by the lab in its model card Best so far
0% 20% 40% 60% 80% 100% 2025 2026 2027 Near the ceiling (85%) Qwen 3.8 Max Kimi K2.5 GPT-5.2 Codex Kimi K2 o1 0% 20% 40% 60% 80% 100% 2025 2026 2027 Near the ceiling (85%) Qwen 3.8 Max Kimi K2.5

Sources: Official PaperBench leaderboard and labs’ model cards

3 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
Meituan
DateLaunch postScoreAs the post writes it
Nov 2, 2026 LongCat-2.5 82.1 PaperBench
Aug 3, 2026 Qwen 3.8 Max 93 PaperBench
Jun 1, 2026 MiniMax-M3 52.6 PaperBench
Apr 28, 2026 Seed2.0 Lite (0428) 52.5 PaperBench
Jan 27, 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
Jan 30, 2026 Kimi K2.5 technical report 63.5 PaperBench (CodeDev) (Table 4) AI R&D risk
Dec 18, 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
Dec 11, 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
Nov 18, 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
Aug 7, 2025 GPT-5 system card 24 PaperBench 10-paper subset (no browsing), pass@1, launch candidate (Figure 25) AI R&D risk
Aug 7, 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
Aug 5, 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
Aug 5, 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
Jul 21, 2025 Kimi K2 technical report 27.8 Paper Bench Code-Dev (Acc.) (Table 3) AI R&D risk
Jul 17, 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
Apr 16, 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
Apr 16, 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

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