Claude Sonnet 5.5 (Xhigh, Default Fallback) vs Step 5 Preview
Which is better for the money: Claude Sonnet 5.5 (Xhigh, Default Fallback) by Anthropic or Step 5 Preview by StepFun? 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
Claude Sonnet 5.5 (Xhigh, Default Fallb… scores 8.2 points higher (51.9 vs 43.7) but costs 1.8× as much to run the benchmark ($2177 vs $1190; flagship vs premium cost classes). Pick Claude Sonnet 5.5 (Xhigh, Default Fallb… when the extra intelligence is worth the premium, otherwise Step 5 Preview.
| Metric | Claude Sonnet 5.5 (Xhigh, Default Fallback) | Step 5 Preview | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 51.9 | 43.7 | −15.8% Step 5 Preview is 15.8% less intelligent |
| Total AA cost (lower is better) | $2,176.82 | $1,190.26 | −45.3% Step 5 Preview is 45.3% cheaper |
| End-to-end time (lower is better) | 30.59s | 12.01s | −60.7% Step 5 Preview is 60.7% faster |
| Price per 1M tokens (in / out) | $2.00 / $10.0 | $1.00 / $2.70 | |
| Input modalities | Text, Image | Text, Image |
Step 5 Preview vs Claude Sonnet 5.5 (Xhigh, Default Fallback): 15.8% less intelligence, 45.3% less cost to run the AA benchmark, and 60.7% faster end-to-end.
Today's Pareto frontier
Against the frontier
- 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.
- Step 5 Preview 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)Step 5 PreviewToday's Pareto frontierOpen-weights frontierEvery other model
Matchup
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