DeepSeek V4 vs GPT-5.5

Pick two tools from the same category to compare side-by-side.

	DeepSeek V4 DeepSeek's V4 generation of open-weight MoE models with 1M-token context and agent-focused reasoning modes.	GPT-5.5 OpenAI's flagship frontier model, positioned as a new class of intelligence for coding and professional work.
Category	model	model
Vendor type	open source	commercial
Pricing	free	usage
Strengths	+ MIT-licensed open weights for both Pro and Flash variants + 1M-token context window + Selectable reasoning effort modes (non-think plus two thinking modes) + Sparse MoE design keeps activated parameters low relative to total size	+ OpenAI's recommended model for complex reasoning and coding + 1M-token context window with up to 128K output tokens + Generally available via the OpenAI API with listed pricing of $5 input / $30 output per million tokens
Tradeoffs	− Branded as a preview release on deepseek.com as of June 2026 − V4-Pro's scale makes self-hosting impractical without large GPU clusters	− Most expensive tier in OpenAI's lineup; GPT-5.4 is positioned as the more affordable option for similar work − API-only commercial model; no open weights
Used in stacks	0	0