Claude Opus 5.5 (High, Default Fallback) vs GPT-6 Luna (Medium)
Which is better for the money: Claude Opus 5.5 (High, Default Fallback) by Anthropic or GPT-6 Luna (Medium) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-24.
Trade-off
Verdict
Depends on your budget
Claude Opus 5.5 (High, Default Fallback) scores 23.7 points higher (53.6 vs 29.9) but costs 70× as much to run the benchmark ($2172 vs $31.2; flagship vs budget cost classes). They are not alternatives at one budget: pick Claude Opus 5.5 (High, Default Fallback) when you need intelligence above 29.9, and GPT-6 Luna (Medium) when 29.9 is enough.
| Metric | Claude Opus 5.5 (High, Default Fallback) | GPT-6 Luna (Medium) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 53.6 | 29.9 | −44.2% GPT-6 Luna (Medium) is 44.2% less intelligent |
| Total AA cost (lower is better) | $2,172.43 | $31.17 | −98.6% GPT-6 Luna (Medium) is 98.6% cheaper |
| End-to-end time (lower is better) | 33.81s | 8.25s | −75.6% GPT-6 Luna (Medium) is 75.6% faster |
| Price per 1M tokens (in / out) | $4.00 / $20.0 | $0.10 / $0.50 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Luna (Medium) vs Claude Opus 5.5 (High, Default Fallback): 44.2% less intelligence, 98.6% less cost to run the AA benchmark, and 75.6% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Opus 5.5 (High, Default Fallback) is on today's frontier: nothing is both smarter and cheaper.
- GPT-6 Luna (Medium) is on today's frontier: nothing is both smarter and cheaper.
Claude Opus 5.5 (High, Default Fallback)GPT-6 Luna (Medium)Today's Pareto frontierEvery other model
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