Claude Sonnet 5.5 (Medium, Default Fallback) vs Step 5 Preview
Which is better for the money: Claude Sonnet 5.5 (Medium, 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 2026-10-24.
Trade-off
Verdict
Depends on your budget
Step 5 Preview scores 2.9 points higher (43.7 vs 40.8) but costs 1.9× as much to run the benchmark ($1190 vs $622; both premium class). Pick Step 5 Preview when the extra intelligence is worth the premium, otherwise Claude Sonnet 5.5 (Medium, Default Fall….
| Metric | Claude Sonnet 5.5 (Medium, Default Fallback) | Step 5 Preview | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 40.8 | 43.7 | +7.1% Step 5 Preview is 7.1% more intelligent |
| Total AA cost (lower is better) | $622.28 | $1,190.26 | +91.3% Step 5 Preview is 91.3% more expensive |
| End-to-end time (lower is better) | 6.26s | 12.06s | +92.7% Step 5 Preview is 92.7% slower |
| 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 (Medium, Default Fallback): 7.1% more intelligence, 91.3% more cost to run the AA benchmark, and 92.7% slower end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Sonnet 5.5 (Medium, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (High) scores 50.20 for $521.
- 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 (Medium, Default Fallback)Step 5 PreviewToday's Pareto frontierOpen-weights frontierEvery other model
Matchup
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Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-sonnet-5-5-medium/step-5 · Markdown: /api/v1/compare/claude-sonnet-5-5-medium/step-5?format=md · llms.txt · agent skill