Claude 4.5 Sonnet (Reasoning) vs GPT-5.5 (Xhigh)
Which is better for the money: Claude 4.5 Sonnet (Reasoning) by Anthropic or GPT-5.5 (Xhigh) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-25.
Trade-off
Verdict
Depends on your budget
GPT-5.5 (Xhigh) scores 17.7 points higher (38.4 vs 20.7) but costs 3.5× as much to run the benchmark ($5294 vs $1501; flagship vs premium cost classes). They are not alternatives at one budget: pick GPT-5.5 (Xhigh) when you need intelligence above 20.7, and Claude 4.5 Sonnet (Reasoning) when 20.7 is enough.
| Metric | Claude 4.5 Sonnet (Reasoning) | GPT-5.5 (Xhigh) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 20.7 | 38.4 | +85.5% GPT-5.5 (Xhigh) is 85.5% more intelligent |
| Total AA cost (lower is better) | $1,501.22 | $5,294.36 | +252.7% GPT-5.5 (Xhigh) is 3.5× more expensive |
| End-to-end time (lower is better) | 20.86s | 40.04s | +91.9% GPT-5.5 (Xhigh) is 91.9% slower |
| Price per 1M tokens (in / out) | $3.00 / $15.0 | $5.00 / $30.0 | |
| Input modalities | Text, Image | Text, Image |
GPT-5.5 (Xhigh) vs Claude 4.5 Sonnet (Reasoning): 85.5% more intelligence, 252.7% more cost to run the AA benchmark, and 91.9% 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.
- GPT-5.5 (Xhigh) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Xhigh, Default Fallback) scores 56.00 for $4057.
Claude 4.5 Sonnet (Reasoning)GPT-5.5 (Xhigh)Today's Pareto frontierEvery other model
Matchup
Compare something else
Agents:
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-4-5-sonnet-thinking/gpt-5-5 · Markdown: /api/v1/compare/claude-4-5-sonnet-thinking/gpt-5-5?format=md · llms.txt · agent skill