Head to head
SpaceXAI: Grok 4.6 vs OpenAI: GPT-5.6 Luna
Live prices, context windows, capabilities, and measured quality — updated continuously.
Side by side
| Metric | SpaceXAI: Grok 4.6 Xai | OpenAI: GPT-5.6 Luna Openai |
|---|---|---|
| Input $/M tokens | $2.00 | $0.200 |
| Output $/M tokens | $6.00 | $1.20 |
| Context window | 500K | 1.1M |
| Max output | — | 128K |
| WM Score | 90 | 87 |
| Benchmark quality | 94.8 | 83.7 |
| Hosts serving it | 1 | 3 |
| Throughput (tok/s) | 50 | 99.5 |
| Latency (ms) | 1260 | 865 |
| Vision | ||
| Tools | ||
| Reasoning | ||
| JSON mode |
Which should you pick?
OpenAI: GPT-5.6 Luna costs less per million input tokens — about 10.0× cheaper than SpaceXAI: Grok 4.6. SpaceXAI: Grok 4.6 scores higher on measured quality. OpenAI: GPT-5.6 Luna takes a larger context window, which matters for long documents or big codebases. Prices here are live list prices; the same model can cost less on a different host, so check the model page for the cheapest offering.