BIG-Bench Extra Hard
Models solve harder replacements for each of the 23 BIG-Bench Hard tasks, 4,520 examples in total. The score is a harmonic mean of task accuracies.
A mini version with 460 examples also exists, so check which one a model card reports. Labs usually print the micro average, which the BBEH micro average record holds.
- Made by
- Google DeepMind
- Released
- February 2025
- Kind
- Language reasoning
- Level
- University
- Scored
- Checked automatically
- Answers
- Short answer
- Tasks
- All public
- Strongest model tested
- o3-mini #124 on the capability index
- Last model added
- March 2025
- Scores refreshed
- November 12th, 2026
In the authors’ words
Large language models (LLMs) are increasingly deployed in everyday applications, demanding robust general reasoning capabilities and diverse reasoning skillset. However, current LLM reasoning benchmarks predominantly focus on mathematical and coding abilities, leaving a gap in evaluating broader reasoning proficiencies. One particular exception is the BIG-Bench dataset, which has served as a crucial benchmark for evaluating the general reasoning capabilities of LLMs, thanks to its diverse set of challenging tasks that allowed for a comprehensive assessment of general reasoning across various skills within a unified framework. However, recent advances in LLMs have led to saturation on BIG-Bench, and its harder version BIG-Bench Hard (BBH). State-of-the-art models achieve near-perfect scores on many tasks in BBH, thus diminishing its utility. To address this limitation, we introduce BIG-Bench Extra Hard (BBEH), a new benchmark designed to push the boundaries of LLM reasoning evaluation. BBEH replaces each task in BBH with a novel task that probes a similar reasoning capability but exhibits significantly increased difficulty. We evaluate various models on BBEH and observe a (harmonic) average accuracy of 9.8% for the best general-purpose model and 44.8% for the best reasoning-specialized model, indicating substantial room for improvement and highlighting the ongoing challenge of achieving robust general reasoning in LLMs. We release BBEH publicly at: https://github.com/google-deepmind/bbeh.
o3-mini leads with 44.8% among models released by March 2025
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 March 2025, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- Claude Fable 5.2
-
Gemini 4 Carbon
- GPT-6 Astra
- Claude Opus 5.5
- and 16 more
- 1 o3-mini high 44.8%
- 2
Gemini 2.0 Flash Feb 2025 9.80%
- 3
Gemini 2.0 Flash-Lite 8.00%
- 4
DeepSeek-R1 6.80%
- 5 GPT-4o Jan 2025 6.00%
- 6
DeepSeek-R1-Distill-Qwen-32B 5.20%
- 7
Gemma 3 27B 4.90%
- 8
Gemma 3 12B 4.50%
- 9
Gemma 2 27B 4.00%
- 10
Llama 3.1-8B 3.60%
- 11
Gemma 3 4B 3.40%
Source: Official BIG-Bench Extra Hard leaderboard
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | o3-mini | 44.8% | high | Jan 2025 | Official leaderboard |
| 2 | | 9.80% | Feb 2025 | Official leaderboard | |
| 3 | | 8.00% | Feb 2025 | Official leaderboard | |
| 4 | | 6.80% | Jan 2025 | Official leaderboard | |
| 5 | GPT-4o Jan 2025 | 6.00% | Jan 2025 | Official leaderboard | |
| 6 | | 5.20% | Jan 2025 | Official leaderboard | |
| 7 | | 4.90% | Mar 2025 | Official leaderboard | |
| 8 | | 4.50% | Mar 2025 | Official leaderboard | |
| 9 | | 4.00% | Jun 2024 | Official leaderboard | |
| 10 | | 3.60% | Jul 2024 | Official leaderboard | |
| 11 | | 3.40% | Mar 2025 | Official leaderboard |
Number one over time
Lab claims count from the day the card came out, independent runs from the model’s release.
Source: Official BIG-Bench Extra Hard leaderboard
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Source: Official BIG-Bench Extra Hard 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.
Versions
More in Knowledge
- MMLU-Pro In use Harder 10-option version of MMLU with reasoning-focused questions across 14 subjects.
Intern-S2-397B 89.8%
- SuperGPQA In use 26,529 graduate-level multiple-choice questions across 285 disciplines. Accuracy.
Qwen 3.6 Max (Preview) 73.9%
- WideSearch In use 200 bilingual broad info-seeking tasks: agent collects many atomic facts into a table. Scored by success rate and row/item F1.
Tencent Hy4 preview 83.9%
- BBEH micro average In use Models solve harder replacements for each of the 23 BIG-Bench Hard tasks, 4,520 examples in total. The score is the share of all examples answered correctly.
Gemma 4 31B IT 74.4%
- KMMLU-Pro In use Models answer multiple-choice questions taken from Korean National Professional Licensure exams. It tests professional knowledge used in Korean industry.
Solar Pro 4 79.2%
- HLE-Verified In use Verified and revised version of Humanity's Last Exam (1,811 items) with uncertain items removed.
Seed2.0 Pro 73.6%