Claude 4.5 Haiku (Reasoning) vs Claude Fable 5.1 (Low, Default Fallback)
Which is better for the money: Claude 4.5 Haiku (Reasoning) by Anthropic or Claude Fable 5.1 (Low, Default Fallback) by Anthropic? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-26.
Depends on your budget
Claude Fable 5.1 (Low, Default Fallback) scores 29.9 points higher (46.8 vs 16.9) but costs 5.3× as much to run the benchmark ($3158 vs $594; flagship vs premium cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (Low, Default Fallback) when you need intelligence above 16.9, and Claude 4.5 Haiku (Reasoning) when 16.9 is enough.
| Metric | Claude 4.5 Haiku (Reasoning) | Claude Fable 5.1 (Low, Default Fallback) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 16.9 | 46.8 | +176.9% Claude Fable 5.1 (Low… is 2.8× more intelligent |
| Total AA cost (lower is better) | $594.08 | $3,157.66 | +431.5% Claude Fable 5.1 (Low… is 5.3× more expensive |
| End-to-end time (lower is better) | 24.36s | 10.92s | −55.2% Claude Fable 5.1 (Low… is 55.2% faster |
| Price per 1M tokens (in / out) | $1.00 / $5.00 | $10.0 / $50.0 | |
| Input modalities | Text, Image | Text, Image |
Claude Fable 5.1 (Low, Default Fallback) vs Claude 4.5 Haiku (Reasoning): 176.9% more intelligence, 431.5% more cost to run the AA benchmark, and 55.2% faster end-to-end.
Against the frontier
- Claude 4.5 Haiku (Reasoning) is off the frontier: at the same or lower cost, GPT-6.1 Sol (High) scores 50.20 for $521.
- 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.
Compare something else
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-4-5-haiku-reasoning/claude-fable-5-1-low · Markdown: /api/v1/compare/claude-4-5-haiku-reasoning/claude-fable-5-1-low?format=md · llms.txt · agent skill