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

Anthropic · OpenAI · catalog 2026-09-14

Trade-off: Claude Fable 5.1 (Adaptive Reasoning, High Effort, Default Fallback) is cheaper ($7.175 vs $7.7/M); GPT-6 Astra (xhigh) scores higher on intelligence (52.5 vs 51.2).

	Claude Fable 5.1 (Adaptive Reasoning, High Effort, Default Fallback)	GPT-6 Astra (xhigh)
Speed (tok/s)	49.2 measured	51.1 measured
Blended $/M	$7.175 derived	$7.7 derived
Intelligence index	51.2 measured	52.5 measured
TTFT (ms)	1241 measured	13589 measured
Context	—	—
Coding index	79 measured	76 measured
Agentic index	53 measured	51 measured

Claude Fable 5.1 (Adaptive Reasoning, High 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.