Claude Sonnet 5.5 (Medium, Default Fallback) vs GPT-6 Luna (Low)
Which is better for the money: Claude Sonnet 5.5 (Medium, Default Fallback) by Anthropic or GPT-6 Luna (Low) 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 Sonnet 5.5 (Medium, Default Fall… scores 19.3 points higher (40.8 vs 21.5) but costs 59× as much to run the benchmark ($622 vs $10.6; 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 21.5, and GPT-6 Luna (Low) when 21.5 is enough.
| Metric | Claude Sonnet 5.5 (Medium, Default Fallback) | GPT-6 Luna (Low) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 40.8 | 21.5 | −47.3% GPT-6 Luna (Low) is 47.3% less intelligent |
| Total AA cost (lower is better) | $622.28 | $10.63 | −98.3% GPT-6 Luna (Low) is 98.3% cheaper |
| End-to-end time (lower is better) | 6.13s | 7.32s | +19.4% GPT-6 Luna (Low) is 19.4% slower |
| Price per 1M tokens (in / out) | $2.00 / $10.0 | $0.10 / $0.50 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Luna (Low) vs Claude Sonnet 5.5 (Medium, Default Fallback): 47.3% less intelligence, 98.3% less cost to run the AA benchmark, and 19.4% slower end-to-end.
Today's Pareto frontier
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 (Low) is on today's frontier: nothing is both smarter and cheaper.
Claude Sonnet 5.5 (Medium, Default Fallback)GPT-6 Luna (Low)Today's Pareto frontierEvery other model
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