Claude Sonnet 5.5 (High, Default Fallback) vs GPT-5.6 Luna (Low)
Which is better for the money: Claude Sonnet 5.5 (High, Default Fallback) by Anthropic or GPT-5.6 Luna (Low) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-27.
Trade-off
Verdict
Depends on your budget
Claude Sonnet 5.5 (High, Default Fallba… scores 25.8 points higher (46.8 vs 21.0) but costs 38× as much to run the benchmark ($1027 vs $27.0; premium vs budget cost classes). They are not alternatives at one budget: pick Claude Sonnet 5.5 (High, Default Fallba… when you need intelligence above 21.0, and GPT-5.6 Luna (Low) when 21.0 is enough.
| Metric | Claude Sonnet 5.5 (High, Default Fallback) | GPT-5.6 Luna (Low) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 46.8 | 21.0 | −55.1% GPT-5.6 Luna (Low) is 55.1% less intelligent |
| Total AA cost (lower is better) | $1,027.40 | $27.02 | −97.4% GPT-5.6 Luna (Low) is 97.4% cheaper |
| End-to-end time (lower is better) | 16.58s | 5.68s | −65.7% GPT-5.6 Luna (Low) is 65.7% faster |
| Price per 1M tokens (in / out) | $2.00 / $10.0 | $0.20 / $1.20 | |
| Input modalities | Text, Image | Text, Image |
GPT-5.6 Luna (Low) vs Claude Sonnet 5.5 (High, Default Fallback): 55.1% less intelligence, 97.4% less cost to run the AA benchmark, and 65.7% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Sonnet 5.5 (High, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Xhigh) scores 51.00 for $662.
- GPT-5.6 Luna (Low) is off the frontier: at the same or lower cost, GPT-6 Luna (Low) scores 21.50 for $10.6.
Claude Sonnet 5.5 (High, Default Fallback)GPT-5.6 Luna (Low)Today's Pareto frontierEvery other model
Matchup
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Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-sonnet-5-5-high/gpt-5-6-luna-low · Markdown: /api/v1/compare/claude-sonnet-5-5-high/gpt-5-6-luna-low?format=md · llms.txt · agent skill