Claude Fable 5.1 (Medium, Default Fallback) vs GPT-6 Luna (High)
Which is better for the money: Claude Fable 5.1 (Medium, 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 2026-10-26.
Trade-off
Verdict
Depends on your budget
Claude Fable 5.1 (Medium, Default Fallb… scores 16.0 points higher (48.9 vs 32.9) but costs 83× as much to run the benchmark ($3983 vs $47.9; flagship vs budget cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (Medium, Default Fallb… when you need intelligence above 32.9, and GPT-6 Luna (High) when 32.9 is enough.
| Metric | Claude Fable 5.1 (Medium, Default Fallback) | GPT-6 Luna (High) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 48.9 | 32.9 | −32.7% GPT-6 Luna (High) is 32.7% less intelligent |
| Total AA cost (lower is better) | $3,983.28 | $47.85 | −98.8% GPT-6 Luna (High) is 98.8% cheaper |
| End-to-end time (lower is better) | 19.49s | 18.94s | −2.8% GPT-6 Luna (High) is 2.8% 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 (Medium, Default Fallback): 32.7% less intelligence, 98.8% less cost to run the AA benchmark, and 2.8% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Fable 5.1 (Medium, Default Fallback) is off the frontier: at the same or lower cost, Kimi K3.1 Pro scores 55.10 for $3117.
- GPT-6 Luna (High) is on today's frontier: nothing is both smarter and cheaper.
Claude Fable 5.1 (Medium, Default Fallback)GPT-6 Luna (High)Today's Pareto frontierEvery other model
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