Claude Fable 5.1 (High, Default Fallback) vs GPT-6 Luna (High)
Which is better for the money: Claude Fable 5.1 (High, Default Fallback) by Anthropic or GPT-6 Luna (High) 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 Fable 5.1 (High, Default Fallbac… scores 18.3 points higher (51.2 vs 32.9) but costs 110× as much to run the benchmark ($5242 vs $47.9; flagship vs budget cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (High, Default Fallbac… when you need intelligence above 32.9, and GPT-6 Luna (High) when 32.9 is enough.
| Metric | Claude Fable 5.1 (High, Default Fallback) | GPT-6 Luna (High) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 51.2 | 32.9 | −35.7% GPT-6 Luna (High) is 35.7% less intelligent |
| Total AA cost (lower is better) | $5,241.59 | $47.85 | −99.1% GPT-6 Luna (High) is 99.1% cheaper |
| End-to-end time (lower is better) | 25.53s | 21.41s | −16.1% GPT-6 Luna (High) is 16.1% faster |
| Price per 1M tokens (in / out) | $10.0 / $50.0 | $0.10 / $0.50 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Luna (High) vs Claude Fable 5.1 (High, Default Fallback): 35.7% less intelligence, 99.1% less cost to run the AA benchmark, and 16.1% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Fable 5.1 (High, Default Fallback) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Xhigh, Default Fallback) scores 56.00 for $4057.
- GPT-6 Luna (High) is on today's frontier: nothing is both smarter and cheaper.
Claude Fable 5.1 (High, Default Fallback)GPT-6 Luna (High)Today's Pareto frontierEvery other model
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