Claude Fable 5.1 (Low, Default Fallback) vs GPT-5.6 Luna (Non-reasoning)
Which is better for the money: Claude Fable 5.1 (Low, Default Fallback) by Anthropic or GPT-5.6 Luna (Non-reasoning) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-27.
Depends on your budget
Claude Fable 5.1 (Low, Default Fallback) scores 31.3 points higher (46.8 vs 15.5) but costs 137× as much to run the benchmark ($3158 vs $23.0; flagship vs budget cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (Low, Default Fallback) when you need intelligence above 15.5, and GPT-5.6 Luna (Non-reasoning) when 15.5 is enough.
| Metric | Claude Fable 5.1 (Low, Default Fallback) | GPT-5.6 Luna (Non-reasoning) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 46.8 | 15.5 | −66.9% GPT-5.6 Luna (Non-rea… is 66.9% less intelligent |
| Total AA cost (lower is better) | $3,157.66 | $22.97 | −99.3% GPT-5.6 Luna (Non-rea… is 99.3% cheaper |
| End-to-end time (lower is better) | 10.69s | 5.19s | −51.4% GPT-5.6 Luna (Non-rea… is 51.4% 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 (Non-reasoning) vs Claude Fable 5.1 (Low, Default Fallback): 66.9% less intelligence, 99.3% less cost to run the AA benchmark, and 51.4% faster end-to-end.
Against the frontier
- Claude Fable 5.1 (Low, Default Fallback) is off the frontier: at the same or lower cost, Kimi K3.1 Pro scores 55.10 for $3117.
- GPT-5.6 Luna (Non-reasoning) is off the frontier: at the same or lower cost, GPT-6 Luna (Low) scores 21.50 for $10.6.
Compare something else
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-fable-5-1-low/gpt-5-6-luna-non-reasoning · Markdown: /api/v1/compare/claude-fable-5-1-low/gpt-5-6-luna-non-reasoning?format=md · llms.txt · agent skill