DeepSeek V4 Flash is $4.87 cheaper per 1M input tokens (97.5% lower; 39.7x difference).
API cost decision in 10 seconds
🔥DeepSeek V4 Flash vs 🔥GPT-5.5
Pick DeepSeek V4 Flash for lower cost; pick GPT-5.5 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 Flash for lower cost; pick GPT-5.5 only if the larger context window matters more.
On the standard 1M input plus 500K output workload, DeepSeek V4 Flash is estimated at $0.25 vs $20 for GPT-5.5, saving $19.75 (98.7% lower).
Cost-first pickDeepSeek V4 Flash
Context-first pickGPT-5.5
Sample savings$19.7598.7%
10x traffic gap$197.48
GPT-5.5 has more context, but DeepSeek V4 Flash saves $19.75 on the standard workload. At 10x that traffic, the same price gap is about $197.48. Use the calculator below to replace the sample workload with your own token volume.
DeepSeek V4 Flash is $29.75 cheaper per 1M output tokens (99.2% lower; 119x difference).
GPT-5.5 has 1.42K more context (1x larger).
DeepSeek V4 Flash is $19.75 cheaper on the standard workload (98.7% lower).
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 Flash has the lower input price; DeepSeek V4 Flash has the lower output price; GPT-5.5 offers the larger context window. For the 1M input plus 500K output sample, DeepSeek V4 Flash is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.25 for DeepSeek V4 Flash and $20 for GPT-5.5.
Choose DeepSeek V4 Flash when you care most about lower input-token price, and lower output-token price.
Choose GPT-5.5 when you care most about larger context window.
- On the standard 1M input plus 500K output workload, DeepSeek V4 Flash is estimated at $0.25 vs $20 for GPT-5.5, saving $19.75 (98.7% lower).
- DeepSeek V4 Flash is $19.75 cheaper on the standard workload (98.7% lower).
- DeepSeek V4 Flash is $4.87 cheaper per 1M input tokens (97.5% lower; 39.7x difference).
- DeepSeek V4 Flash is $29.75 cheaper per 1M output tokens (99.2% lower; 119x difference).
- GPT-5.5 has 1.42K more context (1x larger).
| Feature | 🔥DeepSeek V4 Flash (DeepSeek) | 🔥GPT-5.5 (OpenAI) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.126 | $5 |
| Completion Price per 1M tokens | $0.252 | $30 |
| Sample Workload Cost 1M input + 500K output | $0.25 | $20 |
| Context Window | 1.05M | 1.05M |
| Release Date | 2026-04-24 | 2026-04-24 |
| Popularity Rank current rank | #4 | #19 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | DeepSeek V4 Flash | On the standard 1M input plus 500K output workload, DeepSeek V4 Flash is estimated at $0.25 vs $20 for GPT-5.5, saving $19.75 (98.7% lower). |
| High-volume input processing | DeepSeek V4 Flash | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | DeepSeek V4 Flash | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | GPT-5.5 | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
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Open OpenAI modelsDeepSeek V4 Flash is an efficiency-optimized Mixture-of-Experts model from DeepSeek with 284B total parameters and 13B activated parameters, supporting a 1M-token context window. It is designed for fast inference and...
GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token...