Claude Fable 5.1 vs Claude Opus 5
Claude Fable 5.1 Verdict
- Claude Fable 5.1 (xhigh) and Claude Opus 5 are level on quality (70.3 vs 70.0).
- Claude Fable 5.1 (xhigh) is stronger in composite, knowledge, long context, reasoning.
- Claude Opus 5 is stronger in coding, agents & tools, human preference, maths, multimodal.
- Claude Opus 5 is 2.0× cheaper ($10.00 vs $20.00 per 1M blended).
| Metric | Claude Fable 5.1 (xhigh) | Claude Opus 5 |
|---|---|---|
| BenchLeader Index | 70.3 | 70.0 |
| Coding score | 71.3 | 74.4 |
| Composite score | 95.0 | 92.9 |
| Knowledge score | 84.1 | 70.5 |
| Long context score | 68.1 | 66.2 |
| Reasoning score | 76.4 | 71.1 |
| Agents & tools score | – | 71.6 |
| Human preference score | – | 78.2 |
| Maths score | – | 67.1 |
| Multimodal score | – | 69.4 |
| Blended price $/M | $20.00 | $10.00 |
| Output speed | 58 tok/s | 52 tok/s |
| Time to first answer | 132.0 s | 81.6 s |
| Context window | 1M | 1M |
| GPQA Diamond | – | 92.9% |
| OTIS Mock AIME | – | 97.8% |
| Humanity's Last Exam | 46.5% | – |
| SimpleBench | – | 80.6% |
| SciCode | 60.1% | – |
| WeirdML | – | 86.3% |
| Epoch Capabilities Index | – | 162.6 |
| AA Intelligence Index | 53.2 | 50.7 |
| AA-LCR | 83.0% | 79.3% |
| MMMU-Pro | – | 84.7% |
| AA-Omniscience | 42.4 | 37.1 |
| GPQA Diamond (AA) | 93.4% | 93.2% |
| Humanity's Last Exam (AA) | 58.7% | 54.9% |
| SciCode (AA) | 60.9% | 56.4% |
| LiveCodeBench | – | 89.0% |
| MMLU-Pro | – | 91.6% |
| IOI | – | 91.7% |
| LegalBench | – | 87.0% |
| CorpFin | – | 73.2% |
| TaxEval | – | 75.1% |
| Terminal-Bench 2.1 (Vals) | – | 84.6% |
| SWE-bench (Vals) | – | 97.0% |
| GPQA Diamond (Vals) | – | 93.4% |
| Vals Index | – | 67.2 |
| HiL-Bench | – | 57.0% |
| EQ-Bench 4 | – | 1385 |
| ARC-AGI-1 | 96.5% | – |
| ARC-AGI-2 | 90.0% | – |
Data as of 2026-09-09. Best configuration of each model; every score links to its source on the model pages.