Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) vs Claude Opus 5 (Adaptive Reasoning, High Effort)

Anthropic · Anthropic · catalog 2026-09-14

Claude Opus 5 (Adaptive Reasoning, High Effort) beats Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback): cheaper ($3.85 vs $7.175/M) and at least as smart (index 48.2 vs 47).
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback)Claude Opus 5 (Adaptive Reasoning, High Effort)
Speed (tok/s)47.4 measured50.3 measured
Blended $/M$7.175 derived$3.85 derived
Intelligence index47 measured48.2 measured
TTFT (ms)511 measured1694 measured
Context——
Coding index75 measured77 measured
Agentic index48 measured53 measured

Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) card · Claude Opus 5 (Adaptive Reasoning, High Effort) card · 3D observatory

Verdicts use price×intelligence dominance only, and only where both sides are measured; null cells stay null with their provenance (em-dash = not in catalog). Percentile-free by design — this page compares two models, not the field. Generated page — do not hand-edit.