Claude Opus 5.5 (Xhigh, Default Fallback) vs GPT-6 Luna (Medium)
Which is better for the money: Claude Opus 5.5 (Xhigh, 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 2026-10-26.
Depends on your budget
Claude Opus 5.5 (Xhigh, Default Fallbac… scores 26.1 points higher (56.0 vs 29.9) but costs 130× as much to run the benchmark ($4057 vs $31.2; flagship vs budget cost classes). They are not alternatives at one budget: pick Claude Opus 5.5 (Xhigh, Default Fallbac… when you need intelligence above 29.9, and GPT-6 Luna (Medium) when 29.9 is enough.
| Metric | Claude Opus 5.5 (Xhigh, Default Fallback) | GPT-6 Luna (Medium) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 56.0 | 29.9 | −46.6% GPT-6 Luna (Medium) is 46.6% less intelligent |
| Total AA cost (lower is better) | $4,056.65 | $31.17 | −99.2% GPT-6 Luna (Medium) is 99.2% cheaper |
| End-to-end time (lower is better) | 115.71s | Not reported | — not comparable |
| 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 (Xhigh, Default Fallback): 46.6% less intelligence, 99.2% less cost to run the AA benchmark, and end-to-end time not fully reported.
Against the frontier
- Claude Opus 5.5 (Xhigh, 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.
Compare something else
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-opus-5-5-xhigh/gpt-6-luna-medium · Markdown: /api/v1/compare/claude-opus-5-5-xhigh/gpt-6-luna-medium?format=md · llms.txt · agent skill