Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) | Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) |
|---|---|---|
| Input ($/M tokens) | $10 | $10 |
| Output ($/M tokens) | $50 | $50 |
Verdict. Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) wins the overall benchmark matchup 2–0 across 2 overlapping categories, but raw benchmark score is only one input to the decision.
Pricing. Both models sit in the premium bracket for output-token pricing. At 1.0× the per-million-token cost, Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) makes more sense when output volume is low and absolute reasoning quality justifies the premium.
Strengths. Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) is strongest on Coding Index (81.6), Intelligence Index (65.7). Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) leads on Coding Index (80.7), Intelligence Index (64.8).
Speed. Throughput is comparable — 66 tok/s vs 69 tok/s — so generation speed shouldn't drive your choice here. Look at the per-benchmark wins instead.
Provider. Both models come from the same vendor, so the choice comes down to which tier or generation fits your workload — not vendor lock-in.
Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) costs $1050.00 ($12600/year); Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) costs $1050.00 ($12600/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) ≈ $150.00/run, Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) ≈ $150.00/run. At agent/realtime scale (200M input / 100M output per million requests): Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) ≈ $7000/run, Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) ≈ $7000/run.
Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.
Head-to-head deltas
Data from Artificial Analysis API — 12 benchmarks
Both models have similar pricing. Check the detailed breakdown above for input vs output token costs.
Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) wins 2 out of 12 benchmarks compared to 0 for Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback). See the detailed benchmark chart above for per-category results.
Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) generates tokens faster at 69 tok/s vs 66 tok/s. However, Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) has lower time-to-first-token (111.68s vs 282.34s).
Choose based on your priorities: both are similarly priced, Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) for stronger benchmark performance, and Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) for faster generation. For latency-sensitive apps, check the TTFT comparison above.