deepseek-v4-flash-thinking vs gpt-5.5 Benchmark Comparison

Direct benchmark comparison between deepseek-v4-flash-thinking and gpt-5.5 based on LMArena Elo and the latest 2026 API pricing.

Direct Technical & Pricing Comparison

Frontier Model	LMArena Elo	API Cost (1M)	Throughput
deepseek-v4-flash-thinking	1439	$1.12e-7	55
gpt-5.5	1477	$0.00000125	31

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

Comparison Summary: gpt-5.5 is the more capable model in this pair, leading by 38 Elo points. Notably, both models are on the Pareto Frontier, representing a true trade-off between higher intelligence and lower cost.