Claude Fable 5.1 (High, Default Fallback) vs Claude Sonnet 5 (Medium)
Which is better for the money: Claude Fable 5.1 (High, Default Fallback) by Anthropic or Claude Sonnet 5 (Medium) 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 (High, Default Fallbac… scores 23.1 points higher (51.2 vs 28.1) but costs 4.3× as much to run the benchmark ($5242 vs $1218; flagship vs premium cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (High, Default Fallbac… when you need intelligence above 28.1, and Claude Sonnet 5 (Medium) when 28.1 is enough.
| Metric | Claude Fable 5.1 (High, Default Fallback) | Claude Sonnet 5 (Medium) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 51.2 | 28.1 | −45.1% Claude Sonnet 5 (Medi… is 45.1% less intelligent |
| Total AA cost (lower is better) | $5,241.59 | $1,218.17 | −76.8% Claude Sonnet 5 (Medi… is 76.8% cheaper |
| End-to-end time (lower is better) | 26.71s | 9.17s | −65.7% Claude Sonnet 5 (Medi… is 65.7% faster |
| Price per 1M tokens (in / out) | $10.0 / $50.0 | $2.00 / $10.0 | |
| Input modalities | Text, Image | Text, Image |
Claude Sonnet 5 (Medium) vs Claude Fable 5.1 (High, Default Fallback): 45.1% less intelligence, 76.8% less cost to run the AA benchmark, and 65.7% faster end-to-end.
Against the frontier
- Claude Fable 5.1 (High, Default Fallback) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Xhigh, Default Fallback) scores 56.00 for $4057.
- Claude Sonnet 5 (Medium) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
Compare something else
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-fable-5-1-high/claude-sonnet-5-medium · Markdown: /api/v1/compare/claude-fable-5-1-high/claude-sonnet-5-medium?format=md · llms.txt · agent skill