Claude Fable 5 vs Claude Opus 5.5
Claude Fable 5 Verdict
- Claude Fable 5 (thinking) and Claude Opus 5.5 (thinking) are level on quality (70.3 vs 70.7).
- Claude Fable 5 (thinking) is stronger in agents & tools, instruction following.
- Claude Opus 5.5 (thinking) is stronger in composite, knowledge, long context, reasoning, multimodal.
- Claude Opus 5.5 (thinking) is 2.5× cheaper ($8.00 vs $20.00 per 1M blended).
- Claude Fable 5 (thinking) streams 1.4× faster (67 vs 48 tokens per second).
| Metric | Claude Fable 5 (thinking) | Claude Opus 5.5 (thinking) |
|---|---|---|
| BenchLeader Index | 70.3 | 70.7 |
| Agents & tools score | 74.1 | – |
| Composite score | 89.7 | 95.0 |
| Instruction following score | 63.0 | – |
| Knowledge score | 83.5 | 85.0 |
| Long context score | 67.3 | 68.5 |
| Reasoning score | 90.1 | 95.0 |
| Multimodal score | – | 71.9 |
| Blended price $/M | $20.00 | $8.00 |
| Output speed | 67 tok/s | 48 tok/s |
| Time to first answer | 120.8 s | 4.2 s |
| Context window | 1M | 1M |
| AA Intelligence Index | 49.6 | 57.6 |
| IFBench | 63.5% | – |
| AA-LCR | 82.3% | 84.7% |
| MMMU-Pro | – | 87.7% |
| AA-Omniscience | 43.3 | 46.4 |
| Terminal-Bench Hard | 62.9% | – |
| GPQA Diamond (AA) | 92.6% | – |
| Humanity's Last Exam (AA) | 55.5% | 61.4% |
| SciCode (AA) | 61.0% | 66.9% |
| τ²-Bench Telecom (AA) | 98.5% | – |
| Kagi LLM Benchmark | 91.4% | – |
| CritPt | 28.6% | 31.7% |
| GDPval (AA) | 54.8% | 67.3% |
| τ²-Bench Banking (AA) | 38.1% | – |
| Analyst Agent (AA) | 48.8% | – |
| Terminal-Bench 4.0 (AA) | 42.4% | 59.6% |
| Terminal-Bench 2.1 (AA) | 84.6% | – |
| AutomationBench | 54.1% | 69.5% |
| GDP.pdf | 24.0% | 26.2% |
| MLCR | 64.4% | – |
| Harvey LAB | 93.6% | 91.2% |
| EnterpriseOps-Gym | 51.1% | – |
| AA-Omniscience: accuracy | 65.3% | 66.2% |
| AA-Omniscience: non-hallucination | 36.4% | 41.4% |
| AA-Briefcase | 1543 | 1822 |
Data as of 2026-09-22. Best configuration of each model; every score links to its source on the model pages.
Claude Fable 5 vs Claude Opus 5.5: questions
- Is Claude Fable 5 better than Claude Opus 5.5?
- Claude Fable 5 (thinking) and Claude Opus 5.5 (thinking) are level on quality (70.3 vs 70.7). The BenchLeader Index combines every independent quality benchmark; Claude Opus 5.5 (thinking) is ahead overall as of 2026-09-22, but check the category scores for your use.
- Which is cheaper, Claude Fable 5 or Claude Opus 5.5?
- Claude Opus 5.5 is cheaper: $8.00 against $20.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Fable 5 or Claude Opus 5.5?
- Claude Fable 5 streams faster: 67 against 48 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.