Claude Fable 5 vs Claude Opus 4.5
Claude Fable 5 Verdict
- Claude Fable 5 leads on quality: 70.5 vs 60.7.
- Claude Fable 5 is stronger in coding, composite, human preference, instruction following, knowledge, long context, multimodal, reasoning.
- Claude Opus 4.5 (thinking) is stronger in agents & tools, maths.
- Claude Opus 4.5 (thinking) is 2.0× cheaper ($10.00 vs $20.00 per 1M blended).
- Claude Fable 5 streams 1.4× faster (63 vs 45 tokens per second).
| Metric | Claude Fable 5 | Claude Opus 4.5 (thinking) |
|---|---|---|
| BenchLeader Index | 70.5 | 60.7 |
| Agents & tools score | 74.4 | 74.6 |
| Coding score | 70.5 | 56.4 |
| Composite score | 91.8 | 65.8 |
| Human preference score | 71.6 | – |
| Instruction following score | 62.9 | 54.8 |
| Knowledge score | 71.4 | 61.0 |
| Long context score | 67.8 | 65.2 |
| Multimodal score | 69.7 | 58.0 |
| Reasoning score | 75.9 | 58.6 |
| Maths score | – | 64.0 |
| Blended price $/M | $20.00 | $10.00 |
| Output speed | 63 tok/s | 45 tok/s |
| Time to first answer | 102.3 s | 17.3 s |
| Context window | 1M | 200k |
| Remote Labor Index | 16.1% | – |
| APEX-Agents | 45.0% | – |
| FrontierCode | 53.5% | – |
| Epoch Capabilities Index | 163.4 | – |
| LMArena Text | 1507 | – |
| LMArena Hard Prompts | 1533 | – |
| LMArena Coding | 1551 | – |
| LMArena WebDev | 1628 | – |
| LMArena Vision | 1330 | – |
| AA Intelligence Index | 49.7 | 29.1 |
| IFBench | 63.5% | 58.0% |
| AA-LCR | 82.3% | 77.3% |
| MMMU-Pro | – | 74.0% |
| AA-Omniscience | 43.3 | 14 |
| Terminal-Bench Hard | 62.9% | 47.0% |
| GPQA Diamond (AA) | 92.6% | 86.6% |
| Humanity's Last Exam (AA) | 55.5% | 30.1% |
| SciCode (AA) | 61.0% | – |
| τ²-Bench Telecom (AA) | 98.5% | 89.5% |
| AIME (Vals) | – | 95.4% |
| LiveCodeBench | 89.8% | 83.7% |
| MMLU-Pro | 91.5% | 87.3% |
| IOI | 72.3% | 20.3% |
| LegalBench | 88.6% | 84.6% |
| CorpFin | 71.8% | 65.1% |
| TaxEval | 76.9% | 74.9% |
| MedQA | – | 95.9% |
| MGSM | – | 95.2% |
| Terminal-Bench 2.1 (Vals) | 80.5% | – |
| SWE-bench (Vals) | 95.0% | 76.4% |
| GPQA Diamond (Vals) | 93.2% | 85.9% |
| Vals Index | 66.0 | – |
| MCP Atlas | 83.3% | – |
| MultiChallenge | – | 59.0% |
| PRBench Finance | 53.9% | 46.2% |
| PRBench Legal | 52.6% | 44.2% |
| VISTA | – | 46.4% |
| MultiNRC | – | 48.6% |
| HiL-Bench | 56.3% | – |
| TutorBench | – | 51.2% |
| EQ-Bench 4 | 1340 | – |
| Kagi LLM Benchmark | 88.8% | 80.2% |
| ARC-AGI-1 | – | 80.0% |
| ARC-AGI-2 | – | 37.6% |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
Claude Fable 5 vs Claude Opus 4.5: questions
- Is Claude Fable 5 better than Claude Opus 4.5?
- Claude Fable 5 leads on quality: 70.5 vs 60.7. The BenchLeader Index combines every independent quality benchmark; Claude Fable 5 is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is Claude Fable 5 better than Claude Opus 4.5 for coding?
- Claude Fable 5 scores higher in coding (71 vs 56 on the category index, where 50 is average).
- Is Claude Fable 5 better than Claude Opus 4.5 for agentic tasks?
- Claude Opus 4.5 scores higher in agentic tasks (75 vs 74 on the category index, where 50 is average).
- Which is cheaper, Claude Fable 5 or Claude Opus 4.5?
- Claude Opus 4.5 is cheaper: $10.00 against $20.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Fable 5 or Claude Opus 4.5?
- Claude Fable 5 streams faster: 63 against 45 output tokens per second.
- Which has the larger context window?
- Claude Fable 5 accepts more context: 1M against 200k tokens.