DeepSeek V4 Flash vs GPT-5.6 Luna
DeepSeek V4 Flash and GPT-5.6 Luna are both current production-tier models. DeepSeek V4 Flash is meaningfully cheaper at $0.14 / $0.28 per 1M. DeepSeek V4 Flash leads on coding, reasoning. GPT-5.6 Luna leads on instruction following.
Specs side by side
| Metric | DeepSeek DeepSeek V4 Flash | OpenAI GPT-5.6 Luna |
|---|---|---|
| Input price (per 1M) | $0.14 | $1 |
| Output price (per 1M) | $0.28 | $6 |
| Context window | 1M tokens | 1.1M tokens |
| Speed tier | balanced | fast |
| Open weights | Yes | No |
| EU region | No | Yes |
| Free tier | OpenRouter | No |
| Prompt caching | Yes | Yes |
| Vision input | No | Yes |
| Extended thinking | Yes | Yes |
When to choose each
Choose DeepSeek V4 Flash if…
- Cost is a priority ($0.14 / $0.28 per 1M vs $1 / $6 per 1M)
- You need open weights for self-hosting or fine-tuning
- You want a free tier for prototyping
- Coding is central to your workload
- Reasoning is central to your workload
Choose GPT-5.6 Luna if…
- EU data residency is required
- HIPAA eligibility is required
- You need image input / vision
- Instruction following is central to your workload
Benchmark delta
DeepSeek V4 Flash leads on
- Coding
- Reasoning
GPT-5.6 Luna leads on
- Instruction following
FAQ — DeepSeek V4 Flash vs GPT-5.6 Luna
DeepSeek V4 Flash vs GPT-5.6 Luna — which is better?
DeepSeek V4 Flash and GPT-5.6 Luna are both current production-tier models. DeepSeek V4 Flash is meaningfully cheaper at $0.14 / $0.28 per 1M. DeepSeek V4 Flash leads on coding, reasoning. GPT-5.6 Luna leads on instruction following. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does DeepSeek V4 Flash pricing compare to GPT-5.6 Luna?
DeepSeek V4 Flash costs $0.14 / $0.28 per 1M vs GPT-5.6 Luna at $1 / $6 per 1M. DeepSeek V4 Flash is cheaper on output tokens by roughly 2043%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does DeepSeek V4 Flash or GPT-5.6 Luna have the bigger context window?
GPT-5.6 Luna has a 1.1M-token context window — 1× the 1M context of DeepSeek V4 Flash. Enough for entire codebases, books, or multi-document RAG.
Is there a free tier for DeepSeek V4 Flash or GPT-5.6 Luna?
DeepSeek V4 Flash: yes — Often available free via OpenRouter; official API is extremely cheap ($0.14 cache miss, $0.0028 cached input). GPT-5.6 Luna: no — Low-cost at $1/$6 per 1M; starter credits only.
Which is better for coding — DeepSeek V4 Flash or GPT-5.6 Luna?
DeepSeek V4 Flash leads on coding benchmarks (DeepSeek V4 Flash: 89/100, GPT-5.6 Luna: 85/100). For production coding agents also weigh tool-use performance — DeepSeek V4 Flash scores 84, GPT-5.6 Luna scores 87.