GPT-5.6 Luna (Xhigh) vs Grok 4.6 (Xhigh)
Which is better for the money: GPT-5.6 Luna (Xhigh) by OpenAI or Grok 4.6 (Xhigh) by SpaceXAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-27.
Trade-off
Verdict
Depends on your budget
Grok 4.6 (Xhigh) scores 9.6 points higher (44.2 vs 34.6) but costs 13× as much to run the benchmark ($2242 vs $179; flagship vs mid-range cost classes). They are not alternatives at one budget: pick Grok 4.6 (Xhigh) when you need intelligence above 34.6, and GPT-5.6 Luna (Xhigh) when 34.6 is enough.
| Metric | GPT-5.6 Luna (Xhigh) | Grok 4.6 (Xhigh) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 34.6 | 44.2 | +27.7% Grok 4.6 (Xhigh) is 27.7% more intelligent |
| Total AA cost (lower is better) | $179.33 | $2,241.91 | +1150.2% Grok 4.6 (Xhigh) is 13× more expensive |
| End-to-end time (lower is better) | 45.86s | 40.24s | −12.3% Grok 4.6 (Xhigh) is 12.3% faster |
| Price per 1M tokens (in / out) | $0.20 / $1.20 | $2.00 / $6.00 | |
| Input modalities | Text, Image | Text, Image |
Grok 4.6 (Xhigh) vs GPT-5.6 Luna (Xhigh): 27.7% more intelligence, 1150.2% more cost to run the AA benchmark, and 12.3% faster end-to-end.
Today's Pareto frontier
Against the frontier
- GPT-5.6 Luna (Xhigh) is off the frontier: at the same or lower cost, GPT-6.1 Terra (Medium) scores 41.30 for $175.
- Grok 4.6 (Xhigh) is off the frontier: at the same or lower cost, Claude Opus 5.5 (High, Default Fallback) scores 53.60 for $2172.
GPT-5.6 Luna (Xhigh)Grok 4.6 (Xhigh)Today's Pareto frontierEvery other model
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