Claude Sonnet 5.5 (Medium, Default Fallback) vs GPT-6 Luna (Medium)
Which is better for the money: Claude Sonnet 5.5 (Medium, 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 Sonnet 5.5 (Medium, Default Fall… scores 10.9 points higher (40.8 vs 29.9) but costs 20× as much to run the benchmark ($622 vs $31.2; premium vs budget cost classes). They are not alternatives at one budget: pick Claude Sonnet 5.5 (Medium, Default Fall… when you need intelligence above 29.9, and GPT-6 Luna (Medium) when 29.9 is enough.
| Metric | Claude Sonnet 5.5 (Medium, Default Fallback) | GPT-6 Luna (Medium) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 40.8 | 29.9 | −26.7% GPT-6 Luna (Medium) is 26.7% less intelligent |
| Total AA cost (lower is better) | $622.28 | $31.17 | −95.0% GPT-6 Luna (Medium) is 95.0% cheaper |
| End-to-end time (lower is better) | 6.15s | Not reported | — not comparable |
| Price per 1M tokens (in / out) | $2.00 / $10.0 | $0.10 / $0.50 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Luna (Medium) vs Claude Sonnet 5.5 (Medium, Default Fallback): 26.7% less intelligence, 95.0% less cost to run the AA benchmark, and end-to-end time not fully reported.
Against the frontier
- Claude Sonnet 5.5 (Medium, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (High) scores 50.20 for $521.
- 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-sonnet-5-5-medium/gpt-6-luna-medium · Markdown: /api/v1/compare/claude-sonnet-5-5-medium/gpt-6-luna-medium?format=md · llms.txt · agent skill