DeepSeek V4.1 Flash vs GPT-5.5
DeepSeek V4.1 Flash (DeepSeek) vs GPT-5.5 (OpenAI), compared on price, context, speed and Arabic support. Both run on thalam through one OpenAI-compatible API, so you can switch between them with a single model id change. At a glance, DeepSeek V4.1 Flash is the cheaper option and DeepSeek V4.1 Flash is rated faster.
Specs side by side
| Spec | DeepSeek V4.1 Flash | GPT-5.5 |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Type | Text | Text |
| Context window | 1M | 1M |
| Max output | 384K | 128K |
| Input price | $0.300 / 1M | $5.00 / 1M |
| Output price | $1.20 / 1M | $30.00 / 1M |
| Speed | Fast | Medium |
| Arabic support | Strong | Strong |
Which should you choose?
- Lower cost, about 16.7× cheaper ($0.300 / 1M)
- Rated faster (Fast) for latency-sensitive workloads
- OpenAI's flagship GPT-5.5. Top-tier general intelligence, coding, and agentic tasks with a 1M-token context
One OpenAI-compatible endpoint, one bill. Switch between them with a single model id change, pay per use, credits never expire.
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FAQ
What's the difference between DeepSeek V4.1 Flash and GPT-5.5?
DeepSeek V4.1 Flash costs less ($0.300 / 1M vs $5.00 / 1M); DeepSeek V4.1 Flash is rated faster. Both are available on thalam behind one OpenAI-compatible API.
Is DeepSeek V4.1 Flash or GPT-5.5 cheaper?
DeepSeek V4.1 Flash is cheaper on input ($0.300 / 1M vs $5.00 / 1M). On thalam you pay per use, so you can route cheap-by-default and fall back to the other only when needed.
Can I use both DeepSeek V4.1 Flash and GPT-5.5 with one API key?
Yes. thalam is OpenAI-compatible, so both models are reachable through the same endpoint. Switching between them is a one-line model id change, no code rewrite.