GPT-5.6 Luna (Xhigh) vs GPT-6 Astra (Low)
Which is better for the money: GPT-5.6 Luna (Xhigh) by OpenAI or GPT-6 Astra (Low) by OpenAI? 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
GPT-6 Astra (Low) scores 11.2 points higher (45.8 vs 34.6) but costs 8.6× as much to run the benchmark ($1537 vs $179; premium vs mid-range cost classes). They are not alternatives at one budget: pick GPT-6 Astra (Low) when you need intelligence above 34.6, and GPT-5.6 Luna (Xhigh) when 34.6 is enough.
| Metric | GPT-5.6 Luna (Xhigh) | GPT-6 Astra (Low) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 34.6 | 45.8 | +32.4% GPT-6 Astra (Low) is 32.4% more intelligent |
| Total AA cost (lower is better) | $179.33 | $1,536.78 | +757.0% GPT-6 Astra (Low) is 8.6× more expensive |
| End-to-end time (lower is better) | 45.86s | 12.08s | −73.7% GPT-6 Astra (Low) is 73.7% faster |
| Price per 1M tokens (in / out) | $0.20 / $1.20 | $10.0 / $50.0 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Astra (Low) vs GPT-5.6 Luna (Xhigh): 32.4% more intelligence, 757.0% more cost to run the AA benchmark, and 73.7% 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.
- GPT-6 Astra (Low) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
GPT-5.6 Luna (Xhigh)GPT-6 Astra (Low)Today's Pareto frontierEvery other model
Matchup
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Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/gpt-5-6-luna-xhigh/gpt-6-astra-low · Markdown: /api/v1/compare/gpt-5-6-luna-xhigh/gpt-6-astra-low?format=md · llms.txt · agent skill