DeepSeek V4 Flash 0731 is a sparse mixture-of-experts model from DeepSeek, with 13B active parameters out of 284B total. This re-post-trained revision is suited for coding, reasoning, and agent workflows.
Model details →DeepSeek: DeepSeek V4 Flash 0731 vs OpenAI: GPT-5.6 Luna Pro
DeepSeek: DeepSeek V4 Flash 0731 and OpenAI: GPT-5.6 Luna Pro are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://devel…
Model details →Side-by-side comparison
| Capability | DeepSeek: DeepSeek V4 Flash 0731 | OpenAI: GPT-5.6 Luna Pro | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1.0M | 1.1M | 🏆 OpenAI: GPT-5.6 Luna Pro |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $0.09 | $0.10 | 🏆 DeepSeek: DeepSeek V4 Flash 0731 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $0.18 | $0.60 | 🏆 DeepSeek: DeepSeek V4 Flash 0731 |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | — | Yes | 🏆 OpenAI: GPT-5.6 Luna Pro |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is DeepSeek: DeepSeek V4 Flash 0731 better than OpenAI: GPT-5.6 Luna Pro?
DeepSeek: DeepSeek V4 Flash 0731 and OpenAI: GPT-5.6 Luna Pro are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
What's the price difference between DeepSeek: DeepSeek V4 Flash 0731 and OpenAI: GPT-5.6 Luna Pro?
Input: $0.09 vs $0.10 per 1M tokens. Output: $0.18 vs $0.60 per 1M tokens.
What context windows do DeepSeek: DeepSeek V4 Flash 0731 and OpenAI: GPT-5.6 Luna Pro support?
DeepSeek: DeepSeek V4 Flash 0731 supports up to 1.0M tokens. OpenAI: GPT-5.6 Luna Pro supports up to 1.1M tokens.
Do both DeepSeek: DeepSeek V4 Flash 0731 and OpenAI: GPT-5.6 Luna Pro support tool calling?
DeepSeek: DeepSeek V4 Flash 0731: yes. OpenAI: GPT-5.6 Luna Pro: yes.