High-volume, cost-sensitive work
Choose DeepSeek V4 Flash 0731
DeepSeek V4 Flash 0731 costs 26% less on a typical mix of three input tokens for every output token ($0.15 against $0.20 per million tokens).
DeepSeek V4 Flash 0731 vs GPT-6 Luna Pro: price, context and capabilities
Choose DeepSeek V4 Flash 0731 for high-volume, cost-sensitive work and writing and code generation. Choose GPT-6 Luna Pro for reused prompts and documents (RAG, agents), images as input and the latest release.
In short
- DeepSeek V4 Flash 0731 is 26% cheaper than GPT-6 Luna Pro at the headline price ($0.1488 / 1M tokens vs $0.20 / 1M tokens).
- GPT-6 Luna Pro reads more per request: 1.05M tokens against 1.05M.
- GPT-6 Luna Pro is the newer model (Sep 22, 2026, against Jul 31, 2026).
- Only GPT-6 Luna Pro offers vision.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose DeepSeek V4 Flash 0731
DeepSeek V4 Flash 0731 charges $0.24 per million output tokens, against $0.50 for GPT-6 Luna Pro. Output dominates the bill when answers are long.
Reused prompts and documents (RAG, agents)
Choose GPT-6 Luna Pro
GPT-6 Luna Pro charges $0.01 per million cached input tokens, against $0.02 for DeepSeek V4 Flash 0731.
Images as input
Choose GPT-6 Luna Pro
GPT-6 Luna Pro accepts images as input; DeepSeek V4 Flash 0731 does not.
Latest release
Choose GPT-6 Luna Pro
GPT-6 Luna Pro is the newer release (Sep 22, 2026, against Jul 31, 2026 for DeepSeek V4 Flash 0731).
Monthly cost at three volumes
| Volume | DeepSeek V4 Flash 0731 | GPT-6 Luna Pro | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $0.18 | $0.23 | DeepSeek V4 Flash 0731, $0.05 less |
| Production: 20M input, 5M output tokens | $3.57 | $4.50 | DeepSeek V4 Flash 0731, $0.93 less |
| Scale: 500M input, 100M output tokens | $83.30 | $100.00 | DeepSeek V4 Flash 0731, $16.70 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| DeepSeek V4 Flash 0731 | GPT-6 Luna Pro | |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $0.1488 / 1M tokens | $0.20 / 1M tokens |
| Input | $0.119 / 1M tokens | $0.10 / 1M tokens |
| Output | $0.238 / 1M tokens | $0.50 / 1M tokens |
| Cached input | $0.0238 / 1M tokens | $0.01 / 1M tokens |
| Context window | 1.05M | 1.05M |
| Max output | 944k | 128k |
| Released | Jul 31, 2026 | Sep 22, 2026 |
| Knowledge cutoff | No data | No data |
| Licence | Proprietary | Proprietary |
| Capabilities | Reasoning, Tool calling, Structured output, Prompt caching | Vision, Reasoning, Tool calling, Structured output, Prompt caching |
| API model id | deepseek-v4-flash-0731 | gpt-6-luna-pro |
Frequently asked questions
Should I choose DeepSeek V4 Flash 0731 or GPT-6 Luna Pro?
Choose DeepSeek V4 Flash 0731 for high-volume, cost-sensitive work and writing and code generation. Choose GPT-6 Luna Pro for reused prompts and documents (RAG, agents), images as input and the latest release.
Which is cheaper, DeepSeek V4 Flash 0731 or GPT-6 Luna Pro?
DeepSeek V4 Flash 0731 is 26% cheaper than GPT-6 Luna Pro at the headline price ($0.1488 / 1M tokens vs $0.20 / 1M tokens).
Which has the larger context window, DeepSeek V4 Flash 0731 or GPT-6 Luna Pro?
GPT-6 Luna Pro reads more per request: 1.05M tokens against 1.05M.
What is the difference between DeepSeek V4 Flash 0731 and GPT-6 Luna Pro?
DeepSeek V4 Flash 0731 is made by DeepSeek and GPT-6 Luna Pro by OpenAI. DeepSeek V4 Flash 0731 is 26% cheaper than GPT-6 Luna Pro at the headline price ($0.1488 / 1M tokens vs $0.20 / 1M tokens). GPT-6 Luna Pro reads more per request: 1.05M tokens against 1.05M. GPT-6 Luna Pro is the newer model (Sep 22, 2026, against Jul 31, 2026). Only GPT-6 Luna Pro offers vision.
How much do DeepSeek V4 Flash 0731 and GPT-6 Luna Pro cost per month?
At 20 million input and 5 million output tokens a month, DeepSeek V4 Flash 0731 costs $3.57 and GPT-6 Luna Pro costs $4.50, at standard rates.
Which is newer, DeepSeek V4 Flash 0731 or GPT-6 Luna Pro?
GPT-6 Luna Pro was released on Sep 22, 2026 and DeepSeek V4 Flash 0731 on Jul 31, 2026.