AI model comparison
DeepSeek V4 Flash 0731 vs GPT-5.6 Luna Pro
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
DeepSeek
DeepSeek V4 Flash 0731
DeepSeek V4 Flash 0731 is a sparse mixture-of-experts model from DeepSeek, with 13B active parameters out of 284B total.
- Input / 1M
- $0.00
- Output / 1M
- $1.28
- Context
- 1.05M
OpenAI
GPT-5.6 Luna Pro
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.
- Input / 1M
- $0.20
- Output / 1M
- $1.20
- Context
- 1.05M
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
DeepSeek V4 Flash 0731
1.5x cheaper for a typical chat
Higher intelligence score
Tie
Not enough benchmark data
Larger context window
GPT-5.6 Luna Pro
1.05M vs 1.05M tokens
Newer release
DeepSeek V4 Flash 0731
Released July 31, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
DeepSeek V4 Flash 073134.3GPT-5.6 Luna ProNot availableCoding index
DeepSeek V4 Flash 073169.1GPT-5.6 Luna ProNot availableAgentic index
DeepSeek V4 Flash 073141GPT-5.6 Luna ProNot availablePricing
DeepSeek V4 Flash 0731 vs GPT-5.6 Luna Pro API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | DeepSeek V4 Flash 0731 | GPT-5.6 Luna Pro |
|---|---|---|
| Input tokensPer 1M tokens | $0.00 | $0.20 |
| Output tokensPer 1M tokens | $1.28 | $1.20 |
| Cached input (read)Per 1M tokens | $0.00 | $0.02 |
| Cache writePer 1M tokens | Not available | $0.25 |
| Long-context pricingPer 1M tokens, for very long prompts | Same rate at any length | $0.40 in / $1.80 out above 272K |
| Web searchPer request | Not available | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
DeepSeek V4 Flash 0731$0.65GPT-5.6 Luna Pro$1Coding task
30K in, 4K out
DeepSeek V4 Flash 0731$5.26$5.26 cachedGPT-5.6 Luna Pro$10.80$5.40 cachedLong document summary
150K in, 2K out
DeepSeek V4 Flash 0731$3.28$3.28 cachedGPT-5.6 Luna Pro$32.40$5.40 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | DeepSeek V4 Flash 0731 | GPT-5.6 Luna Pro |
|---|---|---|
| Context window | 1.05M tokens | 1.05M tokens |
| Max output | 944K tokens | 128K tokens |
| Input types | Text | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, High, Low | Max, Extra high, High, Medium, Low, None |
| Default reasoning effort | High | Medium |
| Release date | July 31, 2026 | July 9, 2026 |
Features
Supported features
API features available for each model.
| Metric | DeepSeek V4 Flash 0731 | GPT-5.6 Luna Pro |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Supported | Not supported |
| Stop sequences | Supported | Not supported |
| Deterministic seed | Supported | Supported |
| Verbosity control | Not supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
DeepSeek V4 Flash 0731View full model details- DeepSeek V4 Flash 0731 vs DeepSeek V4.1 Flash
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- DeepSeek V4 Flash 0731 vs GPT-6 Luna
- DeepSeek V4 Flash 0731 vs Claude Opus 5.5
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- DeepSeek V4 Flash 0731 vs Qwen3.7 Max
- DeepSeek V4 Flash 0731 vs GLM 5
GPT-5.6 Luna ProView full model details- GPT-5.6 Luna Pro vs DeepSeek V4.1 Flash
- GPT-5.6 Luna Pro vs GLM 5.3 Flash
- GPT-5.6 Luna Pro vs Hy4 preview
- GPT-5.6 Luna Pro vs GPT-6 Luna
- GPT-5.6 Luna Pro vs DeepSeek V4 Flash 0423
- GPT-5.6 Luna Pro vs GPT-5.6 Luna
- GPT-5.6 Luna Pro vs MiniMax M3
- GPT-5.6 Luna Pro vs GPT-5.4 Nano
- GPT-5.6 Luna Pro vs GPT-4.1 Mini
Our take
DeepSeek V4 Flash 0731 is 1.5x cheaper for a typical chat. GPT-5.6 Luna Pro has the larger context window (1.05M vs 1.05M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is DeepSeek V4 Flash 0731 or GPT-5.6 Luna Pro cheaper?
DeepSeek V4 Flash 0731 is cheaper for a typical chat (2K input tokens and 500 output tokens). DeepSeek V4 Flash 0731 costs $0.00 per 1M input tokens and $1.28 per 1M output tokens, while GPT-5.6 Luna Pro costs $0.20 per 1M input tokens and $1.20 per 1M output tokens.
Which has a bigger context window, DeepSeek V4 Flash 0731 or GPT-5.6 Luna Pro?
GPT-5.6 Luna Pro supports up to 1.05M tokens of context, compared with 1.05M for DeepSeek V4 Flash 0731.
Can I use DeepSeek V4 Flash 0731 and GPT-5.6 Luna Pro at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see DeepSeek V4 Flash 0731 and GPT-5.6 Luna Pro answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to DeepSeek V4 Flash 0731 and GPT-5.6 Luna Pro at the same time. Compare the answers side by side and keep the best one.