Claude Opus 5.5 (High, Default Fallback) vs GPT-5.6 Luna (High)
Which is better for the money: Claude Opus 5.5 (High, Default Fallback) by Anthropic or GPT-5.6 Luna (High) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-26.
Trade-off
Verdict
Depends on your budget
Claude Opus 5.5 (High, Default Fallback) scores 21.5 points higher (53.6 vs 32.1) but costs 20× as much to run the benchmark ($2172 vs $108; flagship vs mid-range cost classes). They are not alternatives at one budget: pick Claude Opus 5.5 (High, Default Fallback) when you need intelligence above 32.1, and GPT-5.6 Luna (High) when 32.1 is enough.
| Metric | Claude Opus 5.5 (High, Default Fallback) | GPT-5.6 Luna (High) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 53.6 | 32.1 | −40.1% GPT-5.6 Luna (High) is 40.1% less intelligent |
| Total AA cost (lower is better) | $2,172.43 | $108.15 | −95.0% GPT-5.6 Luna (High) is 95.0% cheaper |
| End-to-end time (lower is better) | 41.01s | 16.71s | −59.3% GPT-5.6 Luna (High) is 59.3% faster |
| Price per 1M tokens (in / out) | $4.00 / $20.0 | $0.20 / $1.20 | |
| Input modalities | Text, Image | Text, Image |
GPT-5.6 Luna (High) vs Claude Opus 5.5 (High, Default Fallback): 40.1% less intelligence, 95.0% less cost to run the AA benchmark, and 59.3% 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-5.6 Luna (High) is off the frontier: at the same or lower cost, Claude Haiku 5.5 (High) scores 37.80 for $94.1.
Claude Opus 5.5 (High, Default Fallback)GPT-5.6 Luna (High)Today's Pareto frontierEvery other model
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Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-opus-5-5-high/gpt-5-6-luna-high · Markdown: /api/v1/compare/claude-opus-5-5-high/gpt-5-6-luna-high?format=md · llms.txt · agent skill