claude-sonnet-4-6 vs grok-4.20-beta-0309-reasoning Benchmark Comparison

Direct benchmark comparison between claude-sonnet-4-6 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-sonnet-4-6	1461	$0.000003	45
grok-4.20-beta-0309-reasoning	1479	$0.000002	107

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

Comparison Summary: These models are highly competitive, with a negligible Elo gap of only 18 points. The choice between them should be driven by specific API features or provider preference.