GPT-6 Luna scores 46.8 on the Respan Index (#30), ahead of Muse Spark 1.2 at 46.6 (#31). Muse Spark 1.2 leads on 8 of the 15 benchmarks both report. GPT-6 Luna is 10x cheaper per token at list price. GPT-6 Luna has the larger context window (1.1M tokens).
* Estimated: no published scores in that category. How the Respan Index works
| LiveBench Instruction Following (LiveBench) |
| 55.9% |
| 74.3% |
| LiveBench Language (LiveBench) | 73.8% | 78.6% |
| LiveBench Mathematics (LiveBench) | 89.1% | 91.2% |
| LiveBench Reasoning (LiveBench) | 81.8% | 90% |
| SAGE (Vals AI) | 48.1% | 47.7% |
| SimpleQA Verified | 41.4% | 60.3% |
| Terminal-Bench 4.0 (Vals AI) | 13.6% | 6.1% |
| LMArena Agent (LMArena) | 0.0135 | -0.0327 |
| LMArena Elo | 1443 | 1494 |
| LMArena WebDev (LMArena) | 1579 | 1532 |
| DeepSWE v1.1 | 66.6% | 59.3% |
Higher is better. Each score links to where it was published.