claude-sonnet-4-5-20250929 vs gemini-3-flash Benchmark Comparison

Direct benchmark comparison between claude-sonnet-4-5-20250929 and gemini-3-flash based on LMArena Elo and the latest 2026 API pricing.

Direct Technical & Pricing Comparison

Frontier Model	LMArena Elo	API Cost (1M)	Throughput
claude-sonnet-4-5-20250929	1451	$0.000003	37
gemini-3-flash	1474	$5e-7	83

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

Comparison Summary: These models are highly competitive, with a negligible Elo gap of only 23 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.