DeepSeek V4 Pro vs GPT-5.5 Pro

DeepSeek V4 Pro and GPT-5.5 Pro are both current production-tier models. DeepSeek V4 Pro is meaningfully cheaper at $0.43 / $0.87 per 1M. DeepSeek V4 Pro has a 1M context window — about 3× the 400k of GPT-5.5 Pro. GPT-5.5 Pro leads on coding, reasoning, general knowledge.

Specs side by side

Metric
DeepSeek
DeepSeek V4 Pro
OpenAI
GPT-5.5 Pro
Input price (per 1M)$0.435$30
Output price (per 1M)$0.87$180
Context window1M tokens400k tokens
Speed tierbalancedslow
Open weightsYesNo
EU regionNoNo
Free tierNoNo
Prompt cachingYesYes
Vision inputNoYes
Extended thinkingYesYes

When to choose each

DeepSeek

Choose DeepSeek V4 Pro if…

  • Cost is a priority ($0.43 / $0.87 per 1M vs $30 / $180 per 1M)
  • You need 1M context (3× more than GPT-5.5 Pro)
  • You need open weights for self-hosting or fine-tuning
OpenAI

Choose GPT-5.5 Pro if…

  • HIPAA eligibility is required
  • You need image input / vision
  • Coding is central to your workload
  • Reasoning is central to your workload

Benchmark delta

DeepSeek V4 Pro leads on

DeepSeek V4 Pro has no meaningful benchmark lead in this pair.

GPT-5.5 Pro leads on

  • Coding
  • Reasoning
  • General knowledge
  • Instruction following
  • Multilingual
  • Tool use

FAQ — DeepSeek V4 Pro vs GPT-5.5 Pro

DeepSeek V4 Pro vs GPT-5.5 Pro — which is better?

DeepSeek V4 Pro and GPT-5.5 Pro are both current production-tier models. DeepSeek V4 Pro is meaningfully cheaper at $0.43 / $0.87 per 1M. DeepSeek V4 Pro has a 1M context window — about 3× the 400k of GPT-5.5 Pro. GPT-5.5 Pro leads on coding, reasoning, general knowledge. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does DeepSeek V4 Pro pricing compare to GPT-5.5 Pro?

DeepSeek V4 Pro costs $0.43 / $0.87 per 1M vs GPT-5.5 Pro at $30 / $180 per 1M. DeepSeek V4 Pro is cheaper on output tokens by roughly 20590%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does DeepSeek V4 Pro or GPT-5.5 Pro have the bigger context window?

DeepSeek V4 Pro has a 1M-token context window — 3× the 400k context of GPT-5.5 Pro. Enough for entire codebases, books, or multi-document RAG.

Is there a free tier for DeepSeek V4 Pro or GPT-5.5 Pro?

DeepSeek V4 Pro: no — No free tier on the official API — but at $0.435/$0.87 per 1M it is near-free vs frontier peers. GPT-5.5 Pro: no — Paid-only — no free tier.

Which is better for coding — DeepSeek V4 Pro or GPT-5.5 Pro?

GPT-5.5 Pro leads on coding benchmarks (DeepSeek V4 Pro: 91/100, GPT-5.5 Pro: 96/100). For production coding agents also weigh tool-use performance — DeepSeek V4 Pro scores 86, GPT-5.5 Pro scores 94.