Claude Fable 5.1 (Medium, Default Fallback) vs Claude Sonnet 5 (Low)
Which is better for the money: Claude Fable 5.1 (Medium, Default Fallback) by Anthropic or Claude Sonnet 5 (Low) 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 (Medium, Default Fallb… scores 24.6 points higher (48.9 vs 24.3) but costs 6.1× as much to run the benchmark ($3983 vs $653; flagship vs premium cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (Medium, Default Fallb… when you need intelligence above 24.3, and Claude Sonnet 5 (Low) when 24.3 is enough.
| Metric | Claude Fable 5.1 (Medium, Default Fallback) | Claude Sonnet 5 (Low) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 48.9 | 24.3 | −50.3% Claude Sonnet 5 (Low) is 50.3% less intelligent |
| Total AA cost (lower is better) | $3,983.28 | $652.70 | −83.6% Claude Sonnet 5 (Low) is 83.6% cheaper |
| End-to-end time (lower is better) | 16.07s | 8.64s | −46.2% Claude Sonnet 5 (Low) is 46.2% faster |
| Price per 1M tokens (in / out) | $10.0 / $50.0 | $2.00 / $10.0 | |
| Input modalities | Text, Image | Text, Image |
Claude Sonnet 5 (Low) vs Claude Fable 5.1 (Medium, Default Fallback): 50.3% less intelligence, 83.6% less cost to run the AA benchmark, and 46.2% faster end-to-end.
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.
- Claude Sonnet 5 (Low) is off the frontier: at the same or lower cost, GPT-6.1 Sol (High) scores 50.20 for $521.
Compare something else
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-fable-5-1-medium/claude-sonnet-5-low · Markdown: /api/v1/compare/claude-fable-5-1-medium/claude-sonnet-5-low?format=md · llms.txt · agent skill