GPT-5.5 (Xhigh) vs GPT-6 Luna (Max)
Which is better for the money: GPT-5.5 (Xhigh) by OpenAI or GPT-6 Luna (Max) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-25.
Trade-off
Verdict
Depends on your budget
GPT-5.5 (Xhigh) scores 0.3 points higher (38.4 vs 38.1) but costs 43× as much to run the benchmark ($5294 vs $122; flagship vs mid-range cost classes). They are not alternatives at one budget: pick GPT-5.5 (Xhigh) when you need intelligence above 38.1, and GPT-6 Luna (Max) when 38.1 is enough.
| Metric | GPT-5.5 (Xhigh) | GPT-6 Luna (Max) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 38.4 | 38.1 | −0.8% GPT-6 Luna (Max) is 0.8% less intelligent |
| Total AA cost (lower is better) | $5,294.36 | $122.05 | −97.7% GPT-6 Luna (Max) is 97.7% cheaper |
| End-to-end time (lower is better) | 55.87s | 84.41s | +51.1% GPT-6 Luna (Max) is 51.1% slower |
| Price per 1M tokens (in / out) | $5.00 / $30.0 | $0.10 / $0.50 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Luna (Max) vs GPT-5.5 (Xhigh): 0.8% less intelligence, 97.7% less cost to run the AA benchmark, and 51.1% slower end-to-end.
Today's Pareto frontier
Against the frontier
- GPT-5.5 (Xhigh) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Xhigh, Default Fallback) scores 56.00 for $4057.
- GPT-6 Luna (Max) is on today's frontier: nothing is both smarter and cheaper.
GPT-5.5 (Xhigh)GPT-6 Luna (Max)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-5-5/gpt-6-luna · Markdown: /api/v1/compare/gpt-5-5/gpt-6-luna?format=md · llms.txt · agent skill