Claude Fable 5.1 vs GPT-6 Luna
Claude Fable 5.1 
GPT-6 Luna Verdict
- Claude Fable 5.1 (high) leads on quality: 70.8 vs 61.2.
- Claude Fable 5.1 (high) is stronger in agents & tools, coding, composite, knowledge, long context, reasoning.
- GPT-6 Luna (max) is stronger in multimodal.
- GPT-6 Luna (max) is 100× cheaper ($0.200 vs $20.00 per 1M blended).
- GPT-6 Luna (max) streams 2.8× faster (157 vs 56 tokens per second).
| Metric | Claude Fable 5.1 (high) | GPT-6 Luna (max) |
|---|---|---|
| BenchLeader Index | 70.8 | 61.2 |
| Agents & tools score | 64.4 | – |
| Coding score | 73.0 | – |
| Composite score | 90.6 | 73.9 |
| Knowledge score | 81.8 | 63.2 |
| Long context score | 67.7 | 67.5 |
| Reasoning score | 81.0 | 76.1 |
| Multimodal score | – | 59.2 |
| Blended price $/M | $20.00 | $0.200 |
| Output speed | 56 tok/s | 157 tok/s |
| Time to first answer | 26.2 s | 142.6 s |
| Context window | 1M | 1.1M |
| Terminal-Bench | 54.5% | – |
| SciCode | 57.6% | – |
| WeirdML | 92.3% | – |
| APEX-Agents | 59.7% | – |
| AA Intelligence Index | 51.1 | 37.3 |
| AA-LCR | 83.7% | 83.3% |
| MMMU-Pro | – | 75.5% |
| AA-Omniscience | 40.8 | 0.7 |
| GPQA Diamond (AA) | 90.6% | – |
| Humanity's Last Exam (AA) | 55.9% | 38.5% |
| SciCode (AA) | 58.7% | 54.6% |
| ARC-AGI-1 | 96.0% | – |
| ARC-AGI-2 | 88.8% | – |
| CritPt | 30.3% | 19.4% |
| GDPval (AA) | 55.9% | 43.4% |
| τ²-Bench Banking (AA) | 43.1% | – |
| MirrorCode | 73.3% | – |
| LMCA | 65.1% | – |
| DTBench | 96.5% | – |
| CursorBench | 49.2% | – |
| ALE-Bench | 2143.2 | – |
| GDP.pdf | 29.6% | – |
| Terminal-Bench 4.0 (AA) | 52.0% | 12.6% |
| Terminal-Bench 2.1 (AA) | 89.9% | – |
| AutomationBench | 55.3% | 53.2% |
| GDP.pdf | 26.8% | 20.4% |
| MLCR | – | 16.1% |
| Harvey LAB | 93.0% | – |
| AA-Omniscience: accuracy | 64.9% | 43.8% |
| AA-Omniscience: non-hallucination | 31.2% | 23.3% |
| AA-Briefcase | 1592 | 1299 |
Data as of 2026-09-23. Best configuration of each model; every score links to its source on the model pages.
Claude Fable 5.1 vs GPT-6 Luna: questions
- Is Claude Fable 5.1 better than GPT-6 Luna?
- Claude Fable 5.1 (high) leads on quality: 70.8 vs 61.2. The BenchLeader Index combines every independent quality benchmark; Claude Fable 5.1 (high) is ahead overall as of 2026-09-23, but check the category scores for your use.
- Which is cheaper, Claude Fable 5.1 or GPT-6 Luna?
- GPT-6 Luna is cheaper: $0.200 against $20.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Fable 5.1 or GPT-6 Luna?
- GPT-6 Luna streams faster: 157 against 56 output tokens per second.
- Which has the larger context window?
- GPT-6 Luna accepts more context: 1.1M against 1M tokens.