claude-sonnet-4-5-20250929 vs deepseek-v3.2-exp-thinking Benchmark Comparison

Direct benchmark comparison between claude-sonnet-4-5-20250929 and deepseek-v3.2-exp-thinking 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
deepseek-v3.2-exp-thinking	1425	$2.7e-7	8

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

Comparison Summary: These models are highly competitive, with a negligible Elo gap of only 26 points. The choice between them should be driven by specific API features or provider preference. However, neither model is currently Pareto-optimal. Developers looking for peak efficiency should investigate gpt-5.2-chat-latest-20260210, which offers a superior benchmark-to-price ratio.