DeepSeek V4 Flash 0731 is $0.08 cheaper per 1M input tokens (84% lower; 6.25x difference).
API cost decision in 10 seconds
🔥GPT-6 Luna vs 🔥DeepSeek V4 Flash 0731
Pick DeepSeek V4 Flash 0731 for lower cost; pick GPT-6 Luna only if the larger context window matters more.
Page updated:
Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick DeepSeek V4 Flash 0731 for lower cost; pick GPT-6 Luna only if the larger context window matters more.
On the standard 1M input plus 500K output workload, DeepSeek V4 Flash 0731 is estimated at $0.34 vs $0.35 for GPT-6 Luna, saving $0.01 (4% lower).
Cost-first pickDeepSeek V4 Flash 0731
Context-first pickGPT-6 Luna
Sample savings$0.014%
10x traffic gap$0.14
GPT-6 Luna has more context, but DeepSeek V4 Flash 0731 saves $0.01 on the standard workload. At 10x that traffic, the same price gap is about $0.14. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Cost winner changes by workload shape: input-heavy / RAG favors DeepSeek V4 Flash 0731, balanced workload favors GPT-6 Luna, and output-heavy chatbot favors GPT-6 Luna.
| Workload shape | Token mix | Better pick | GPT-6 Luna | DeepSeek V4 Flash 0731 |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | DeepSeek V4 Flash 0731 | $0.75 | $0.4 |
| Balanced workload | 1M input + 1M output | GPT-6 Luna | $0.6 | $0.66 |
| Output-heavy chatbot | 1M input + 5M output | GPT-6 Luna | $2.6 | $3.22 |
GPT-6 Luna is $0.14 cheaper per 1M output tokens (21.9% lower; 1.28x difference).
GPT-6 Luna has 1.42K more context (1x larger).
DeepSeek V4 Flash 0731 is $0.01 cheaper on the standard workload (4% lower).
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
DeepSeek V4 Flash 0731 has the lower input price; GPT-6 Luna has the lower output price; GPT-6 Luna offers the larger context window. For the 1M input plus 500K output sample, DeepSeek V4 Flash 0731 is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.35 for GPT-6 Luna and $0.34 for DeepSeek V4 Flash 0731.
Choose GPT-6 Luna when you care most about lower output-token price, and larger context window.
Choose DeepSeek V4 Flash 0731 when you care most about lower input-token price.
- On the standard 1M input plus 500K output workload, DeepSeek V4 Flash 0731 is estimated at $0.34 vs $0.35 for GPT-6 Luna, saving $0.01 (4% lower).
- DeepSeek V4 Flash 0731 is $0.01 cheaper on the standard workload (4% lower).
- DeepSeek V4 Flash 0731 is $0.08 cheaper per 1M input tokens (84% lower; 6.25x difference).
- GPT-6 Luna is $0.14 cheaper per 1M output tokens (21.9% lower; 1.28x difference).
- GPT-6 Luna has 1.42K more context (1x larger).
| Feature | 🔥GPT-6 Luna (OpenAI) | 🔥DeepSeek V4 Flash 0731 (DeepSeek) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.1 | $0.016 |
| Completion Price per 1M tokens | $0.5 | $0.64 |
| Sample Workload Cost 1M input + 500K output | $0.35 | $0.34 |
| Context Window | 1.05M | 1.05M |
| Release Date | ||
| Popularity | #7 | #9 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | DeepSeek V4 Flash 0731 | On the standard 1M input plus 500K output workload, DeepSeek V4 Flash 0731 is estimated at $0.34 vs $0.35 for GPT-6 Luna, saving $0.01 (4% lower). |
| High-volume input processing | DeepSeek V4 Flash 0731 | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | GPT-6 Luna | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | GPT-6 Luna | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- gpt-oss-120b (free) can replace GPT-6 Luna when lower sample workload cost matters most: $0.
- gpt-oss-20b (free) can replace GPT-6 Luna when lower sample workload cost matters most: $0.
- gpt-oss-20b can replace GPT-6 Luna when lower sample workload cost matters most: $0.06.
- gpt-oss-20b (batch) can replace GPT-6 Luna when lower sample workload cost matters most: $0.08.
- No larger-context model is currently tracked within a close sample-cost band.
- DeepSeek V4.1 Flash · DeepSeek · #1
- Step 5 Preview · StepFun · #2
- GLM 5.3 Flash · Z.ai · #3
- MiMo-V2.6-Flash · Xiaomi · #4
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