Claude Fable 5.1 vs Gemini 3.1 Pro
Claude Fable 5.1 
Gemini 3.1 Pro Verdict
- Claude Fable 5.1 (xhigh) leads on quality: 70.3 vs 63.9.
- Claude Fable 5.1 (xhigh) is stronger in coding, composite, knowledge, long context, reasoning.
- Gemini 3.1 Pro is stronger in agents & tools, human preference, instruction following, maths, multimodal.
- Gemini 3.1 Pro is 4.4× cheaper ($4.50 vs $20.00 per 1M blended).
- Gemini 3.1 Pro streams 1.9× faster (110 vs 58 tokens per second).
| Metric | Claude Fable 5.1 (xhigh) | Gemini 3.1 Pro |
|---|---|---|
| BenchLeader Index | 70.3 | 63.9 |
| Coding score | 71.3 | 59.8 |
| Composite score | 95.0 | 67.2 |
| Knowledge score | 84.1 | 66.1 |
| Long context score | 68.1 | 67.6 |
| Reasoning score | 76.4 | 69.5 |
| Agents & tools score | – | 63.7 |
| Human preference score | – | 59.6 |
| Instruction following score | – | 69.5 |
| Maths score | – | 60.7 |
| Multimodal score | – | 66.1 |
| Blended price $/M | $20.00 | $4.50 |
| Output speed | 58 tok/s | 110 tok/s |
| Time to first answer | 132.0 s | 30.5 s |
| Context window | 1M | 1.0M |
| GPQA Diamond | – | 94.1% |
| FrontierMath Tiers 1–3 | – | 59.6% |
| FrontierMath Tier 4 | – | 26.8% |
| OTIS Mock AIME | – | 95.6% |
| Humanity's Last Exam | 46.5% | 46.4% |
| Terminal-Bench | – | 80.2% |
| SimpleBench | – | 79.6% |
| SciCode | 60.1% | 58.9% |
| WeirdML | – | 72.1% |
| APEX-Agents | – | 33.5% |
| ProofBench | – | 26.0% |
| GSO-Bench | – | 22.6% |
| Epoch Capabilities Index | – | 155 |
| LMArena Text | – | 1487 |
| LMArena Hard Prompts | – | 1507 |
| LMArena Coding | – | 1521 |
| LMArena WebDev | – | 1447 |
| LMArena Vision | – | 1295 |
| LMArena Agent | – | -5.3 |
| AA Intelligence Index | 53.2 | 30.4 |
| IFBench | – | 77.1% |
| AA-LCR | 83.0% | 82.0% |
| MMMU-Pro | – | 82.4% |
| AA-Omniscience | 42.4 | 31.9 |
| Terminal-Bench Hard | – | 53.8% |
| GPQA Diamond (AA) | 93.4% | 94.1% |
| Humanity's Last Exam (AA) | 58.7% | 47.0% |
| SciCode (AA) | 60.9% | 58.7% |
| τ²-Bench Telecom (AA) | – | 95.6% |
| AIME 2026 | – | 98.3% |
| HMMT February 2026 | – | 94.7% |
| MathArena Apex | – | 60.9% |
| MultiChallenge | – | 71.4% |
| PRBench Finance | – | 41.9% |
| PRBench Legal | – | 44.0% |
| MultiNRC | – | 64.7% |
| HiL-Bench | – | 35.3% |
| TutorBench | – | 53.0% |
| EQ-Bench 4 | – | 1142 |
| ARC-AGI-1 | 96.5% | 98.0% |
| ARC-AGI-2 | 90.0% | 77.1% |
| ARC-AGI-3 | – | 0.4% |
Data as of 2026-09-09. Best configuration of each model; every score links to its source on the model pages.