GPT-6 Luna Pro is $0.02 cheaper per 1M input tokens (16.7% lower; 1.2x difference).
API cost decision in 10 seconds
NewGPT-6 Luna Pro vs DeepSeek Flash Latest
Pick GPT-6 Luna Pro when budget and context both matter.
Page updated:
Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick GPT-6 Luna Pro when budget and context both matter.
On the standard 1M input plus 500K output workload, GPT-6 Luna Pro is estimated at $0.35 vs $0.36 for DeepSeek Flash Latest, saving $0.01 (2.8% lower).
Cost-first pickGPT-6 Luna Pro
Context-first pickGPT-6 Luna Pro
Sample savings$0.012.8%
10x traffic gap$0.1
GPT-6 Luna Pro is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $0.1. 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 GPT-6 Luna Pro, balanced workload favors Tie, and output-heavy chatbot favors DeepSeek Flash Latest.
| Workload shape | Token mix | Better pick | GPT-6 Luna Pro | DeepSeek Flash Latest |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | GPT-6 Luna Pro | $0.75 | $0.84 |
| Balanced workload | 1M input + 1M output | Tie | $0.6 | $0.6 |
| Output-heavy chatbot | 1M input + 5M output | DeepSeek Flash Latest | $2.6 | $2.52 |
DeepSeek Flash Latest is $0.02 cheaper per 1M output tokens (4% lower; 1.04x difference).
GPT-6 Luna Pro has 1.42K more context (1x larger).
GPT-6 Luna Pro is $0.01 cheaper on the standard workload (2.8% 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
GPT-6 Luna Pro has the lower input price; DeepSeek Flash Latest has the lower output price; GPT-6 Luna Pro offers the larger context window. For the 1M input plus 500K output sample, GPT-6 Luna Pro 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 Pro and $0.36 for DeepSeek Flash Latest.
Choose GPT-6 Luna Pro when you care most about lower input-token price, and larger context window.
Choose DeepSeek Flash Latest when you care most about lower output-token price.
- On the standard 1M input plus 500K output workload, GPT-6 Luna Pro is estimated at $0.35 vs $0.36 for DeepSeek Flash Latest, saving $0.01 (2.8% lower).
- GPT-6 Luna Pro is $0.01 cheaper on the standard workload (2.8% lower).
- GPT-6 Luna Pro is $0.02 cheaper per 1M input tokens (16.7% lower; 1.2x difference).
- DeepSeek Flash Latest is $0.02 cheaper per 1M output tokens (4% lower; 1.04x difference).
- GPT-6 Luna Pro has 1.42K more context (1x larger).
| Feature | NewGPT-6 Luna Pro (OpenAI) | DeepSeek Flash Latest (DeepSeek) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.1 | $0.12 |
| Completion Price per 1M tokens | $0.5 | $0.48 |
| Sample Workload Cost 1M input + 500K output | $0.35 | $0.36 |
| Context Window | 1.05M | 1.05M |
| Release Date |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | GPT-6 Luna Pro | On the standard 1M input plus 500K output workload, GPT-6 Luna Pro is estimated at $0.35 vs $0.36 for DeepSeek Flash Latest, saving $0.01 (2.8% lower). |
| High-volume input processing | GPT-6 Luna Pro | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | DeepSeek Flash Latest | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | GPT-6 Luna Pro | 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 Pro when lower sample workload cost matters most: $0.
- gpt-oss-20b (free) can replace GPT-6 Luna Pro when lower sample workload cost matters most: $0.
- gpt-oss-20b can replace GPT-6 Luna Pro when lower sample workload cost matters most: $0.06.
- gpt-oss-20b (batch) can replace GPT-6 Luna Pro when lower sample workload cost matters most: $0.08.
- GLM 5.3 Flash offers 1.31M context with $0.4 sample workload cost.
- DeepSeek V4 Flash 0731 offers 1.31M context with $0.36 sample workload cost.
- GLM Flash Latest offers 1.31M context with $0.2 sample workload cost.
- DeepSeek V4 Flash Latest offers 1.31M context with $0.43 sample workload cost.
- MiMo-V2.6-Pro · Xiaomi · #1
- Qwen3.8 Max (0902) · Qwen · #2
- DeepSeek V4.1 Flash · DeepSeek · #3
- GLM 5.3 Flash · Z.ai · #4
Cheaper alternatives
Review low-cost models sorted by a standard 1M input plus 500K output workload.
Open cheapest modelsLarger context alternatives
Find models with larger context windows for RAG, long documents, and codebase review.
Open largest context modelsProvider catalogs
Compare models within provider hubs before choosing a final API vendor.
Open provider hubsOpenAI catalog
Review all tracked OpenAI models before deciding whether this matchup is the right shortlist.
Open OpenAI modelsDeepSeek catalog
Check other DeepSeek models with comparable pricing, context, or release timing.
Open DeepSeek modelsGPT-6 Luna Pro is the same underlying model as [GPT-6 Luna](https://openrouter.ai/openai/gpt-6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
This model always redirects to the latest model in the DeepSeek Flash family.