GPT-5.4 Pro vs GPT-5.6 Luna
GPT-5.4 Pro Verdict
- GPT-5.4 Pro leads on quality: 64.3 vs 57.9.
- GPT-5.4 Pro is stronger in instruction following, knowledge, multimodal, reasoning.
- GPT-5.6 Luna (xhigh) is stronger in agents & tools, coding, composite, human preference, long context.
- GPT-5.6 Luna (xhigh) is 150× cheaper ($0.450 vs $67.50 per 1M blended).
- GPT-5.6 Luna (xhigh) streams 117.6× faster (118 vs 1 tokens per second).
| Metric | GPT-5.4 Pro | GPT-5.6 Luna (xhigh) |
|---|---|---|
| BenchLeader Index | 64.3 | 57.9 |
| Instruction following score | 67.3 | – |
| Knowledge score | 73.6 | 55.5 |
| Multimodal score | 69.8 | 60.9 |
| Reasoning score | 75.3 | 53.9 |
| Agents & tools score | – | 48.7 |
| Coding score | – | 59.8 |
| Composite score | – | 66.6 |
| Human preference score | – | 65.0 |
| Long context score | – | 65.1 |
| Blended price $/M | $67.50 | $0.450 |
| Output speed | 1 tok/s | 118 tok/s |
| Time to first answer | 6.3 s | 46.5 s |
| Context window | 1.1M | 1.1M |
| Humanity's Last Exam | 44.3% | – |
| SimpleBench | 74.1% | 46.8% |
| SciCode | – | 50.0% |
| Epoch Capabilities Index | 158.9 | – |
| LMArena Text | – | 1453 |
| LMArena Hard Prompts | – | 1473 |
| LMArena Coding | – | 1498 |
| LMArena WebDev | – | 1519 |
| LMArena Vision | – | 1254 |
| LMArena Agent | – | 0.7 |
| AA Intelligence Index | – | 34.8 |
| AA-LCR | – | 81.7% |
| MMMU-Pro | – | 78.5% |
| AA-Omniscience | – | -10.8 |
| GPQA Diamond (AA) | – | 89.5% |
| Humanity's Last Exam (AA) | – | 37.0% |
| SciCode (AA) | – | 50.5% |
| MultiChallenge | 69.2% | – |
| VISTA | 53.9% | – |
| MultiNRC | 62.3% | – |
| TutorBench | 56.6% | – |
| ARC-AGI-1 | – | 87.7% |
| ARC-AGI-2 | – | 47.6% |
| ARC-AGI-3 | – | 0.0% |
Data as of 2026-09-13. Best configuration of each model; every score links to its source on the model pages.
GPT-5.4 Pro vs GPT-5.6 Luna: questions
- Is GPT-5.4 Pro better than GPT-5.6 Luna?
- GPT-5.4 Pro leads on quality: 64.3 vs 57.9. The BenchLeader Index combines every independent quality benchmark; GPT-5.4 Pro is ahead overall as of 2026-09-13, but check the category scores for your use.
- Which is cheaper, GPT-5.4 Pro or GPT-5.6 Luna?
- GPT-5.6 Luna is cheaper: $0.450 against $67.50 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-5.4 Pro or GPT-5.6 Luna?
- GPT-5.6 Luna streams faster: 118 against 1 output tokens per second.
- Which has the larger context window?
- Both accept 1.1M tokens of context.