Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) vs GPT-6 Astra (xhigh)

Anthropic · OpenAI · catalog 2026-09-14

Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) beats GPT-6 Astra (xhigh): cheaper ($7.175 vs $7.7/M) and at least as smart (index 53.2 vs 52.5).
Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback)GPT-6 Astra (xhigh)
Speed (tok/s)57.3 measured51.1 measured
Blended $/M$7.175 derived$7.7 derived
Intelligence index53.2 measured52.5 measured
TTFT (ms)8578 measured13589 measured
Context——
Coding index81 measured76 measured
Agentic index57 measured51 measured

Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) card · GPT-6 Astra (xhigh) 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.