claude-opus-5.5-max vs grok-4.20-beta-0309-reasoning Benchmark Comparison

Direct benchmark comparison between claude-opus-5.5-max and grok-4.20-beta-0309-reasoning based on LMArena Elo and the latest 2026 API pricing.

Direct Technical & Pricing Comparison

Frontier Model	LMArena Elo	API Cost (1M)	Throughput
claude-opus-5.5-max	1818	$0.000004	59
grok-4.20-beta-0309-reasoning	1471	$0.00000125	63

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

Comparison Summary: claude-opus-5.5-max is the more capable model in this pair, leading by 347 Elo points.