GPT-5.6 Luna (Xhigh) vs GPT-6 Astra (High)
Which is better for the money: GPT-5.6 Luna (Xhigh) by OpenAI or GPT-6 Astra (High) 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 (High) scores 16.3 points higher (50.9 vs 34.6) but costs 16× as much to run the benchmark ($2925 vs $179; flagship vs mid-range cost classes). They are not alternatives at one budget: pick GPT-6 Astra (High) 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 (High) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 34.6 | 50.9 | +47.1% GPT-6 Astra (High) is 47.1% more intelligent |
| Total AA cost (lower is better) | $179.33 | $2,925.01 | +1531.1% GPT-6 Astra (High) is 16× more expensive |
| End-to-end time (lower is better) | 45.82s | 59.28s | +29.4% GPT-6 Astra (High) is 29.4% slower |
| Price per 1M tokens (in / out) | $0.20 / $1.20 | $10.0 / $50.0 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Astra (High) vs GPT-5.6 Luna (Xhigh): 47.1% more intelligence, 1531.1% more cost to run the AA benchmark, and 29.4% slower 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 (High) 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)GPT-6 Astra (High)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-high · Markdown: /api/v1/compare/gpt-5-6-luna-xhigh/gpt-6-astra-high?format=md · llms.txt · agent skill