gemini-3-flash vs grok-4.20-beta-0309-reasoning Benchmark Comparison

Direct benchmark comparison between gemini-3-flash 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
gemini-3-flash	1474	$5e-7	67
grok-4.20-beta-0309-reasoning	1480	$0.000002	132

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

Comparison Summary: These models are highly competitive, with a negligible Elo gap of only 6 points. The choice between them should be driven by specific API features or provider preference. Specifically, gemini-3-flash is currently on the Pareto line, suggesting it offers better systemic value for its performance tier.