GPT-5.6 Luna vs Muse Spark 1.3
GPT-5.6 Luna 
Muse Spark 1.3 Verdict
- Muse Spark 1.3 leads on quality: 68.3 vs 59.3.
- GPT-5.6 Luna (xhigh) is stronger in agents & tools, coding, human preference, multimodal, reasoning.
- Muse Spark 1.3 is stronger in composite, knowledge, long context.
- GPT-5.6 Luna (xhigh) is 4.4× cheaper ($0.450 vs $2.00 per 1M blended).
- Muse Spark 1.3 streams 2.1× faster (241 vs 118 tokens per second).
| Metric | GPT-5.6 Luna (xhigh) | Muse Spark 1.3 |
|---|---|---|
| BenchLeader Index | 59.3 | 68.3 |
| Agents & tools score | 48.7 | – |
| Coding score | 59.8 | – |
| Composite score | 73.3 | 90.3 |
| Human preference score | 64.8 | – |
| Knowledge score | 59.3 | 79.1 |
| Long context score | 67.6 | 68.2 |
| Multimodal score | 61.8 | – |
| Reasoning score | 53.9 | – |
| Blended price $/M | $0.450 | $2.00 |
| Output speed | 118 tok/s | 241 tok/s |
| Time to first answer | 47.7 s | 30.5 s |
| Context window | 1.1M | 1.0M |
| SimpleBench | 46.8% | – |
| SciCode | 50.0% | – |
| LMArena Text | 1453 | – |
| LMArena Hard Prompts | 1473 | – |
| LMArena Coding | 1498 | – |
| LMArena WebDev | 1519 | – |
| LMArena Vision | 1259 | – |
| LMArena Agent | 0.7 | – |
| AA Intelligence Index | 34.8 | 48.2 |
| AA-LCR | 81.7% | 83.0% |
| MMMU-Pro | 78.5% | – |
| AA-Omniscience | -10.8 | 25 |
| GPQA Diamond (AA) | 89.5% | 93.5% |
| Humanity's Last Exam (AA) | 37.0% | 48.7% |
| SciCode (AA) | 50.5% | 58.8% |
| PRBench Finance | – | 59.5% |
| PRBench Legal | – | 61.6% |
| ARC-AGI-1 | 87.7% | – |
| ARC-AGI-2 | 47.6% | – |
| ARC-AGI-3 | 0.0% | – |
Data as of 2026-09-14. Best configuration of each model; every score links to its source on the model pages.
GPT-5.6 Luna vs Muse Spark 1.3: questions
- Is GPT-5.6 Luna better than Muse Spark 1.3?
- Muse Spark 1.3 leads on quality: 68.3 vs 59.3. The BenchLeader Index combines every independent quality benchmark; Muse Spark 1.3 is ahead overall as of 2026-09-14, but check the category scores for your use.
- Which is cheaper, GPT-5.6 Luna or Muse Spark 1.3?
- GPT-5.6 Luna is cheaper: $0.450 against $2.00 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-5.6 Luna or Muse Spark 1.3?
- Muse Spark 1.3 streams faster: 241 against 118 output tokens per second.
- Which has the larger context window?
- GPT-5.6 Luna accepts more context: 1.1M against 1.0M tokens.