Claude Fable 5.1 (Max, Default Fallback) vs Step 5 Preview
Which is better for the money: Claude Fable 5.1 (Max, 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 (Max, Default Fallback) scores 9.7 points higher (53.4 vs 43.7) but costs 11× as much to run the benchmark ($13129 vs $1190; flagship vs premium cost classes). They are not alternatives at one budget: pick Claude Fable 5.1 (Max, Default Fallback) when you need intelligence above 43.7, and Step 5 Preview when 43.7 is enough.
| Metric | Claude Fable 5.1 (Max, Default Fallback) | Step 5 Preview | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 53.4 | 43.7 | −18.2% Step 5 Preview is 18.2% less intelligent |
| Total AA cost (lower is better) | $13,128.86 | $1,190.26 | −90.9% Step 5 Preview is 90.9% cheaper |
| End-to-end time (lower is better) | 201.72s | 12.06s | −94.0% Step 5 Preview is 94.0% 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 (Max, Default Fallback): 18.2% less intelligence, 90.9% less cost to run the AA benchmark, and 94.0% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Fable 5.1 (Max, Default Fallback) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Max, Default Fallback) scores 57.60 for $8708.
- 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 (Max, Default Fallback)Step 5 PreviewToday's Pareto frontierOpen-weights frontierEvery other model
Matchup
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