gpt-5.5 vs grok-4-1-fast-reasoning Benchmark Comparison

Direct benchmark comparison between gpt-5.5 and grok-4-1-fast-reasoning based on LMArena Elo and the latest 2026 API pricing.

Direct Technical & Pricing Comparison

Frontier Model	LMArena Elo	API Cost (1M)	Throughput
gpt-5.5	1476	$0.00000125	94
grok-4-1-fast-reasoning	1431	$2e-7	77

*These models represent the Pareto Frontier (optimal cost-to-performance).*

Comparison Summary: gpt-5.5 is the more capable model in this pair, leading by 45 Elo points. However, neither model is currently Pareto-optimal. Developers looking for peak efficiency should investigate claude-opus-4-6-thinking, which offers a superior benchmark-to-price ratio.