DeepSeek V4 Pro vs GPT-5.5
Side-by-side comparison of pricing, context window, modalities, licensing, and strengths — with practical guidance on which model fits which workload.
| Spec | DeepSeek V4 Pro | GPT-5.5 |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Context window | 1M tokens | 1M tokens |
| Input price (per 1M tokens) | $0.44 | $5.00 |
| Output price (per 1M tokens) | $0.87 | $30.00 |
| Example workload (10M in + 2M out) | $6.14 / month | $110.00 / month |
| Modalities | text, code | text, image, audio, code |
| Knowledge cutoff | Not disclosed | Not disclosed |
| Release date | Apr 2026 | 2026 |
| License | MIT | Proprietary |
| Strengths | 1.6T MoE (49B active), Code & math, Ultra-low cost, Open weights | Flagship reasoning, Agentic tool use, Multimodal, Coding |
| Open weights | Yes | No |
Verdict
The open-weights disruptor against the proprietary flagship, 2026 edition. DeepSeek V4 Pro — a 1.6-trillion-parameter mixture-of-experts with only 49B active per token — costs roughly $0.44/$0.87 per million tokens via API, more than 30× cheaper on output than GPT-5.5, with MIT-licensed weights you can self-host. GPT-5.5 keeps clear advantages in multimodality (image and audio input vs text-only), polish, safety tooling, and ecosystem support. For pure text and code workloads at scale, V4 Pro’s price-performance is extremely hard to beat.
When to choose DeepSeek V4 Pro
Pick DeepSeek V4 Pro for cost-sensitive text/code pipelines, self-hosting, data-residency control, and MIT-license freedom.
When to choose GPT-5.5
Pick GPT-5.5 for image/audio inputs, managed reliability, and the widest tool ecosystem.
Prices and specs reflect published provider information and change frequently — always confirm on the provider's pricing page before committing to a workload.
Frequently asked questions
Which is cheaper: DeepSeek V4 Pro or GPT-5.5?
DeepSeek V4 Pro is cheaper per token: $0.44 input / $0.87 output per 1M tokens, versus $5.00 / $30.00 for GPT-5.5. Actual costs depend on your input-to-output ratio — try the AI cost calculator for your own numbers.
Which has the larger context window?
GPT-5.5 supports 1M tokens versus 1M for DeepSeek V4 Pro — roughly 1.1× more room for documents, code, and conversation history.
Can I self-host either model?
DeepSeek V4 Pro has downloadable weights (MIT), so you can run it on your own hardware. GPT-5.5 is proprietary and only available through its API.
How should I test which model is better for my use case?
Benchmarks are a starting point, not an answer. Run both models on 20–50 examples of your real task and compare outputs blind. Use our token counter to estimate prompt sizes and the cost calculator to project monthly spend before committing.