Claude Fable 5 (Max, Opus 4.8 Fallback) vs Claude Sonnet 5.5 (Low, Default Fallback)
Which is better for the money: Claude Fable 5 (Max, Opus 4.8 Fallback) by Anthropic or Claude Sonnet 5.5 (Low, Default Fallback) by Anthropic? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-24.
Depends on your budget
Claude Fable 5 (Max, Opus 4.8 Fallback) scores 13.7 points higher (49.6 vs 35.9) but costs 23× as much to run the benchmark ($11161 vs $482; 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 35.9, and Claude Sonnet 5.5 (Low, Default Fallbac… when 35.9 is enough.
| Metric | Claude Fable 5 (Max, Opus 4.8 Fallback) | Claude Sonnet 5.5 (Low, Default Fallback) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 49.6 | 35.9 | −27.6% Claude Sonnet 5.5 (Lo… is 27.6% less intelligent |
| Total AA cost (lower is better) | $11,160.86 | $482.13 | −95.7% Claude Sonnet 5.5 (Lo… is 95.7% cheaper |
| End-to-end time (lower is better) | 71.92s | 6.19s | −91.4% Claude Sonnet 5.5 (Lo… is 91.4% faster |
| Price per 1M tokens (in / out) | $10.0 / $50.0 | $2.00 / $10.0 | |
| Input modalities | Text, Image | Text, Image |
Claude Sonnet 5.5 (Low, Default Fallback) vs Claude Fable 5 (Max, Opus 4.8 Fallback): 27.6% less intelligence, 95.7% less cost to run the AA benchmark, and 91.4% faster end-to-end.
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.
- Claude Sonnet 5.5 (Low, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Medium) scores 47.80 for $361.
Compare something else
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-fable-5/claude-sonnet-5-5-low · Markdown: /api/v1/compare/claude-fable-5/claude-sonnet-5-5-low?format=md · llms.txt · agent skill