Claude Opus 5 (Xhigh) vs Claude Sonnet 5.5 (Low, Default Fallback)
Which is better for the money: Claude Opus 5 (Xhigh) 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 2026-10-26.
Trade-off
Verdict
Depends on your budget
Claude Opus 5 (Xhigh) scores 13.8 points higher (49.7 vs 35.9) but costs 12× as much to run the benchmark ($5868 vs $482; flagship vs mid-range cost classes). They are not alternatives at one budget: pick Claude Opus 5 (Xhigh) when you need intelligence above 35.9, and Claude Sonnet 5.5 (Low, Default Fallbac… when 35.9 is enough.
| Metric | Claude Opus 5 (Xhigh) | Claude Sonnet 5.5 (Low, Default Fallback) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 49.7 | 35.9 | −27.8% Claude Sonnet 5.5 (Lo… is 27.8% less intelligent |
| Total AA cost (lower is better) | $5,867.76 | $482.13 | −91.8% Claude Sonnet 5.5 (Lo… is 91.8% cheaper |
| End-to-end time (lower is better) | 40.42s | 5.93s | −85.3% Claude Sonnet 5.5 (Lo… is 85.3% faster |
| Price per 1M tokens (in / out) | $5.00 / $25.0 | $2.00 / $10.0 | |
| Input modalities | Text, Image | Text, Image |
Claude Sonnet 5.5 (Low, Default Fallback) vs Claude Opus 5 (Xhigh): 27.8% less intelligence, 91.8% less cost to run the AA benchmark, and 85.3% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Opus 5 (Xhigh) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Xhigh, Default Fallback) scores 56.00 for $4057.
- Claude Sonnet 5.5 (Low, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Medium) scores 47.80 for $361.
Claude Opus 5 (Xhigh)Claude Sonnet 5.5 (Low, Default Fallback)Today's Pareto frontierEvery other model
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