Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) vs GPT-5.6 Luna (xhigh)

Anthropic · OpenAI · catalog 2026-09-14

GPT-5.6 Luna (xhigh) beats Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort): cheaper ($0.174 vs $1.54/M) and at least as smart (index 34.8 vs 34.7).
Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort)GPT-5.6 Luna (xhigh)
Speed (tok/s)62.4 measured108.3 measured
Blended $/M$1.54 derived$0.174 derived
Intelligence index34.7 measured34.8 measured
TTFT (ms)1399 measured4713 measured
Context——
Coding indexnot measured for both
Agentic indexnot measured for both

Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) card · GPT-5.6 Luna (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.