Claude Fable 5.1 vs Claude Opus 4.1
Claude Fable 5.1 Verdict
- Claude Fable 5.1 (max) leads on quality: 70.3 vs 58.2.
- Claude Fable 5.1 (max) is stronger in agents & tools, coding, composite, human preference, knowledge, maths, reasoning.
- Claude Opus 4.1 (thinking) is stronger in instruction following, long context, multimodal.
- Claude Fable 5.1 (max) is 1.5× cheaper ($20.00 vs $30.00 per 1M blended).
- Claude Fable 5.1 (max) streams 4.0× faster (40 vs 10 tokens per second).
| Metric | Claude Fable 5.1 (max) | Claude Opus 4.1 (thinking) |
|---|---|---|
| BenchLeader Index | 70.3 | 58.2 |
| Agents & tools score | 67.4 | 63.6 |
| Coding score | 78.4 | 53.3 |
| Composite score | 76.6 | 57.9 |
| Human preference score | 71.3 | 64.6 |
| Knowledge score | 75.9 | 58.3 |
| Maths score | 77.0 | 59.3 |
| Reasoning score | 71.9 | 65.6 |
| Instruction following score | – | 52.6 |
| Long context score | – | 64.5 |
| Multimodal score | – | 56.5 |
| Blended price $/M | $20.00 | $30.00 |
| Output speed | 40 tok/s | 10 tok/s |
| Time to first answer | 299.8 s | 3.2 s |
| Context window | 1M | 200k |
| FrontierMath Tiers 1–3 | 90.2% | – |
| FrontierMath Tier 4 | 87.8% | – |
| OTIS Mock AIME | 100.0% | – |
| SimpleQA Verified | 70.8% | – |
| Terminal-Bench | 57.9% | – |
| SciCode | 62.0% | – |
| WeirdML | 92.9% | – |
| ProofBench | 100.0% | – |
| LMArena Text | 1504 | 1450 |
| LMArena Hard Prompts | 1522 | 1480 |
| LMArena Coding | 1517 | 1512 |
| LMArena WebDev | 1764 | – |
| LMArena Agent | 14.5 | – |
| LiveBench | 83.4% | – |
| LiveBench Reasoning | 91.7% | – |
| LiveBench Coding | 86.4% | – |
| LiveBench Agentic Coding | 66.1% | – |
| LiveBench Mathematics | 97.0% | – |
| LiveBench Data Analysis | 80.3% | – |
| LiveBench Language | 89.5% | – |
| AA Intelligence Index | – | 22.9 |
| IFBench | – | 55.4% |
| AA-LCR | – | 76.0% |
| MMMU-Pro | – | 67.9% |
| Terminal-Bench Hard | – | 34.3% |
| GPQA Diamond (AA) | – | 80.9% |
| Humanity's Last Exam (AA) | – | 12.5% |
| τ²-Bench Telecom (AA) | – | 71.4% |
| AIME (Vals) | – | 78.2% |
| LiveCodeBench | – | 66.5% |
| MMLU-Pro | – | 87.9% |
| TaxEval | – | 73.7% |
| MedQA | – | 93.6% |
| MGSM | – | 94.4% |
| GPQA Diamond (Vals) | – | 76.3% |
| MultiChallenge | – | 57.2% |
| VISTA | – | 48.4% |
| MultiNRC | – | 38.4% |
| TutorBench | – | 50.8% |
| ARC-AGI-1 | 97.5% | – |
| ARC-AGI-2 | 90.0% | – |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
Claude Fable 5.1 vs Claude Opus 4.1: questions
- Is Claude Fable 5.1 better than Claude Opus 4.1?
- Claude Fable 5.1 (max) leads on quality: 70.3 vs 58.2. The BenchLeader Index combines every independent quality benchmark; Claude Fable 5.1 (max) is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is Claude Fable 5.1 better than Claude Opus 4.1 for coding?
- Claude Fable 5.1 scores higher in coding (78 vs 53 on the category index, where 50 is average).
- Is Claude Fable 5.1 better than Claude Opus 4.1 for agentic tasks?
- Claude Fable 5.1 scores higher in agentic tasks (67 vs 64 on the category index, where 50 is average).
- Which is cheaper, Claude Fable 5.1 or Claude Opus 4.1?
- Claude Fable 5.1 is cheaper: $20.00 against $30.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Fable 5.1 or Claude Opus 4.1?
- Claude Fable 5.1 streams faster: 40 against 10 output tokens per second.
- Which has the larger context window?
- Claude Fable 5.1 accepts more context: 1M against 200k tokens.