Claude Fable 5.1 (Medium, Default Fallback) vs Step 5 Preview
Which is better for the money: Claude Fable 5.1 (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
Claude Fable 5.1 (Medium, Default Fallb… scores 5.2 points higher (48.9 vs 43.7) but costs 3.3× as much to run the benchmark ($3983 vs $1190; flagship vs premium cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (Medium, Default Fallb… when you need intelligence above 43.7, and Step 5 Preview when 43.7 is enough.
| Metric | Claude Fable 5.1 (Medium, Default Fallback) | Step 5 Preview | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 48.9 | 43.7 | −10.6% Step 5 Preview is 10.6% less intelligent |
| Total AA cost (lower is better) | $3,983.28 | $1,190.26 | −70.1% Step 5 Preview is 70.1% cheaper |
| End-to-end time (lower is better) | 13.16s | 12.06s | −8.4% Step 5 Preview is 8.4% faster |
| Price per 1M tokens (in / out) | $10.0 / $50.0 | $1.00 / $2.70 | |
| Input modalities | Text, Image | Text, Image |
Step 5 Preview vs Claude Fable 5.1 (Medium, Default Fallback): 10.6% less intelligence, 70.1% less cost to run the AA benchmark, and 8.4% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Fable 5.1 (Medium, Default Fallback) is off the frontier: at the same or lower cost, Kimi K3.1 Pro scores 55.10 for $3117.
- Step 5 Preview is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
Claude Fable 5.1 (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-fable-5-1-medium/step-5 · Markdown: /api/v1/compare/claude-fable-5-1-medium/step-5?format=md · llms.txt · agent skill