Claude 4.5 Sonnet (Reasoning) vs Claude Opus 5.5 (Low, Default Fallback)
Which is better for the money: Claude 4.5 Sonnet (Reasoning) by Anthropic or Claude Opus 5.5 (Low, Default Fallback) by Anthropic? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-26.
Clear winner
Verdict
Pick Claude Opus 5.5 (Low, Default Fallback)
Claude Opus 5.5 (Low, Default Fallback) vs Claude 4.5 Sonnet (Reasoning): 104.3% more intelligence, 42.7% less cost to run the AA benchmark, and 45.1% faster end-to-end.
| Metric | Claude 4.5 Sonnet (Reasoning) | Claude Opus 5.5 (Low, Default Fallback) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 20.7 | 42.3 | +104.3% Claude Opus 5.5 (Low,… is 2.0× more intelligent |
| Total AA cost (lower is better) | $1,501.22 | $860.33 | −42.7% Claude Opus 5.5 (Low,… is 42.7% cheaper |
| End-to-end time (lower is better) | 21.00s | 11.52s | −45.1% Claude Opus 5.5 (Low,… is 45.1% faster |
| Price per 1M tokens (in / out) | $3.00 / $15.0 | $4.00 / $20.0 | |
| Input modalities | Text, Image | Text, Image |
Today's Pareto frontier
Against the frontier
- Claude 4.5 Sonnet (Reasoning) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
- Claude Opus 5.5 (Low, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Xhigh) scores 51.00 for $662.
Claude 4.5 Sonnet (Reasoning)Claude Opus 5.5 (Low, Default Fallback)Today's Pareto frontierEvery other model
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Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-4-5-sonnet-thinking/claude-opus-5-5-low · Markdown: /api/v1/compare/claude-4-5-sonnet-thinking/claude-opus-5-5-low?format=md · llms.txt · agent skill