claude-sonnet-4-5-20250929 vs gemini-3.1-pro-preview Benchmark Comparison

Direct benchmark comparison between claude-sonnet-4-5-20250929 and gemini-3.1-pro-preview 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-3.1-pro-preview	1493	$0.000002	80

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

Comparison Summary: gemini-3.1-pro-preview is the more capable model in this pair, leading by 42 Elo points.