Claude Fable 5 (Max, Opus 4.8 Fallback) vs GPT-5.6 Luna (High)
Which is better for the money: Claude Fable 5 (Max, Opus 4.8 Fallback) by Anthropic or GPT-5.6 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 (Max, Opus 4.8 Fallback) scores 17.5 points higher (49.6 vs 32.1) but costs 103× as much to run the benchmark ($11161 vs $108; flagship vs mid-range cost classes). They are not alternatives at one budget: pick Claude Fable 5 (Max, Opus 4.8 Fallback) when you need intelligence above 32.1, and GPT-5.6 Luna (High) when 32.1 is enough.
| Metric | Claude Fable 5 (Max, Opus 4.8 Fallback) | GPT-5.6 Luna (High) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 49.6 | 32.1 | −35.3% GPT-5.6 Luna (High) is 35.3% less intelligent |
| Total AA cost (lower is better) | $11,160.86 | $108.15 | −99.0% GPT-5.6 Luna (High) is 99.0% cheaper |
| End-to-end time (lower is better) | 109.25s | 14.62s | −86.6% GPT-5.6 Luna (High) is 86.6% faster |
| Price per 1M tokens (in / out) | $10.0 / $50.0 | $0.20 / $1.20 | |
| Input modalities | Text, Image | Text, Image |
GPT-5.6 Luna (High) vs Claude Fable 5 (Max, Opus 4.8 Fallback): 35.3% less intelligence, 99.0% less cost to run the AA benchmark, and 86.6% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Fable 5 (Max, Opus 4.8 Fallback) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Max, Default Fallback) scores 57.60 for $8708.
- GPT-5.6 Luna (High) is off the frontier: at the same or lower cost, Claude Haiku 5.5 (High) scores 37.80 for $94.1.
Claude Fable 5 (Max, Opus 4.8 Fallback)GPT-5.6 Luna (High)Today's Pareto frontierEvery other model
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