API cost decision in 10 seconds
GPT-5.5 Pro vs 🔥DeepSeek V4 Pro
Pick DeepSeek V4 Pro for lower cost; pick GPT-5.5 Pro only if the larger context window matters more.
Pricing data updated:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick DeepSeek V4 Pro for lower cost; pick GPT-5.5 Pro only if the larger context window matters more.
On the standard 1M input plus 500K output workload, DeepSeek V4 Pro is estimated at $0.87 vs $120 for GPT-5.5 Pro, saving $119.13 (99.3% lower).
Cost-first pickDeepSeek V4 Pro
Context-first pickGPT-5.5 Pro
Sample savings$119.1399.3%
10x traffic gap$1191.3
GPT-5.5 Pro has more context, but DeepSeek V4 Pro saves $119.13 on the standard workload. At 10x that traffic, the same price gap is about $1191.3. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
DeepSeek V4 Pro stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | GPT-5.5 Pro | DeepSeek V4 Pro |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | DeepSeek V4 Pro | $240 | $2.61 |
| Balanced workload | 1M input + 1M output | DeepSeek V4 Pro | $210 | $1.3 |
| Output-heavy chatbot | 1M input + 5M output | DeepSeek V4 Pro | $930 | $4.78 |
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
DeepSeek V4 Pro has the lower input price, DeepSeek V4 Pro has the lower output price, and GPT-5.5 Pro offers the larger context window.
For a 1M input token plus 500K output token workload, the estimated API cost is $120 for GPT-5.5 Pro and $0.87 for DeepSeek V4 Pro.
Choose GPT-5.5 Pro when you care most about larger context window.
Choose DeepSeek V4 Pro when you care most about lower input-token price, and lower output-token price.
| Feature | GPT-5.5 Pro (OpenAI) | 🔥DeepSeek V4 Pro (DeepSeek) |
|---|---|---|
| Input Price prompt tokens per 1M | $30 | $0.43 |
| Completion Price per 1M tokens | $180 | $0.87 |
| Sample Workload Cost 1M input + 500K output | $120 | $0.87 |
| Context Window | 1.05M | 1.05M |
| Release Date | 2026-04-24 | 2026-04-24 |
| Popularity | #6 |
GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...
DeepSeek V4 Pro is a large-scale Mixture-of-Experts model from DeepSeek with 1.6T total parameters and 49B activated parameters, supporting a 1M-token context window. It is designed for advanced reasoning, coding,...
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | DeepSeek V4 Pro | On the standard 1M input plus 500K output workload, DeepSeek V4 Pro is estimated at $0.87 vs $120 for GPT-5.5 Pro, saving $119.13 (99.3% lower). |
| High-volume input processing | DeepSeek V4 Pro | Lower prompt-token price matters most when prompts or retrieved passages dominate the bill. |
| Long responses and chatbots | DeepSeek V4 Pro | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | GPT-5.5 Pro | A larger context window leaves more room for retrieved passages and source files. |