Claude Opus 5 vs GPT-5.6 Luna
Claude Opus 5 
GPT-5.6 Luna Verdict
- Claude Opus 5 leads on quality: 70.0 vs 59.4.
- Claude Opus 5 is stronger in agents & tools, coding, composite, human preference, knowledge, maths, multimodal, reasoning.
- GPT-5.6 Luna (xhigh) is stronger in long context.
- GPT-5.6 Luna (xhigh) is 22× cheaper ($0.450 vs $10.00 per 1M blended).
- GPT-5.6 Luna (xhigh) streams 2.1× faster (107 vs 51 tokens per second).
| Metric | Claude Opus 5 | GPT-5.6 Luna (xhigh) |
|---|---|---|
| BenchLeader Index | 70.0 | 59.4 |
| Agents & tools score | 71.5 | 50.1 |
| Coding score | 74.5 | 60.0 |
| Composite score | 93.1 | 72.9 |
| Human preference score | 78.2 | 65.0 |
| Knowledge score | 70.6 | 59.0 |
| Long context score | 66.2 | 67.4 |
| Maths score | 67.1 | – |
| Multimodal score | 69.4 | 61.6 |
| Reasoning score | 71.5 | 53.9 |
| Blended price $/M | $10.00 | $0.450 |
| Output speed | 51 tok/s | 107 tok/s |
| Time to first answer | 93.0 s | 55.4 s |
| Context window | 1M | 1M |
| GPQA Diamond | 92.9% | – |
| OTIS Mock AIME | 97.8% | – |
| SimpleBench | 80.6% | 46.8% |
| SciCode | – | 50.0% |
| WeirdML | 86.3% | – |
| Epoch Capabilities Index | 162.6 | – |
| LMArena Text | – | 1453 |
| LMArena Hard Prompts | – | 1473 |
| LMArena Coding | – | 1497 |
| LMArena WebDev | – | 1520 |
| LMArena Vision | – | 1254 |
| LMArena Agent | – | 1.1 |
| AA Intelligence Index | 50.7 | 34.8 |
| AA-LCR | 79.3% | 81.7% |
| MMMU-Pro | 84.7% | 78.5% |
| AA-Omniscience | 37.1 | -10.8 |
| GPQA Diamond (AA) | 93.2% | 89.5% |
| Humanity's Last Exam (AA) | 54.9% | 37.0% |
| SciCode (AA) | 56.4% | 50.5% |
| 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 | – | 87.7% |
| ARC-AGI-2 | – | 47.6% |
| ARC-AGI-3 | – | 0.0% |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 5 vs GPT-5.6 Luna: questions
- Is Claude Opus 5 better than GPT-5.6 Luna?
- Claude Opus 5 leads on quality: 70.0 vs 59.4. The BenchLeader Index combines every independent quality benchmark; Claude Opus 5 is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is Claude Opus 5 better than GPT-5.6 Luna for coding?
- Claude Opus 5 scores higher in coding (75 vs 60 on the category index, where 50 is average).
- Is Claude Opus 5 better than GPT-5.6 Luna for agentic tasks?
- Claude Opus 5 scores higher in agentic tasks (72 vs 50 on the category index, where 50 is average).
- Which is cheaper, Claude Opus 5 or GPT-5.6 Luna?
- GPT-5.6 Luna is cheaper: $0.450 against $10.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 5 or GPT-5.6 Luna?
- GPT-5.6 Luna streams faster: 107 against 51 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.