Claude 4.5 Sonnet (Reasoning) vs Claude Sonnet 5.5 (Xhigh, Default Fallback)
Which is better for the money: Claude 4.5 Sonnet (Reasoning) by Anthropic or Claude Sonnet 5.5 (Xhigh, Default Fallback) by Anthropic? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-26.
Trade-off
Verdict
Depends on your budget
Claude Sonnet 5.5 (Xhigh, Default Fallb… scores 31.2 points higher (51.9 vs 20.7) but costs 1.5× as much to run the benchmark ($2177 vs $1501; flagship vs premium cost classes). Pick Claude Sonnet 5.5 (Xhigh, Default Fallb… when the extra intelligence is worth the premium, otherwise Claude 4.5 Sonnet (Reasoning).
| Metric | Claude 4.5 Sonnet (Reasoning) | Claude Sonnet 5.5 (Xhigh, Default Fallback) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 20.7 | 51.9 | +150.7% Claude Sonnet 5.5 (Xh… is 2.5× more intelligent |
| Total AA cost (lower is better) | $1,501.22 | $2,176.82 | +45.0% Claude Sonnet 5.5 (Xh… is 45.0% more expensive |
| End-to-end time (lower is better) | 21.71s | 33.27s | +53.2% Claude Sonnet 5.5 (Xh… is 53.2% slower |
| Price per 1M tokens (in / out) | $3.00 / $15.0 | $2.00 / $10.0 | |
| Input modalities | Text, Image | Text, Image |
Claude Sonnet 5.5 (Xhigh, Default Fallback) vs Claude 4.5 Sonnet (Reasoning): 150.7% more intelligence, 45.0% more cost to run the AA benchmark, and 53.2% slower end-to-end.
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 Sonnet 5.5 (Xhigh, Default Fallback) is off the frontier: at the same or lower cost, Claude Opus 5.5 (High, Default Fallback) scores 53.60 for $2172.
Claude 4.5 Sonnet (Reasoning)Claude Sonnet 5.5 (Xhigh, Default Fallback)Today's Pareto frontierEvery other model
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