Model comparison - Open weights vs closed
DeepSeek V4.1 Flash vs GPT-6 Luna
DeepSeek V4.1 Flash is from DeepSeek and GPT-6 Luna is from OpenAI. On list price, DeepSeek V4.1 Flash charges 3x GPT-6 Luna's input price ($0.30 vs $0.10 per 1M tokens), and DeepSeek V4.1 Flash charges 2.4x GPT-6 Luna's output price ($1.20 vs $0.50 per 1M tokens). DeepSeek V4.1 Flash has a 1,000,000-token context window and GPT-6 Luna 1,050,000 tokens; max output is 393,216 and 128,000 tokens per response. DeepSeek V4.1 Flash was released on September 10, 2026 and GPT-6 Luna on September 22, 2026. DeepSeek V4.1 Flash publishes open weights (MIT); GPT-6 Luna is closed-weights.
Last verified from each provider's pricing page. All sources
Side-by-side specs
| Spec | DeepSeek V4.1 Flash | GPT-6 Luna |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Input / 1M tokens | $0.30 | $0.10 |
| Output / 1M tokens | $1.20 | $0.50 |
| Cache read / 1M | $0.006 | $0.01 |
| Cache write / 1M | - | $0.125 |
| Batch input / 1M | - | $0.05 |
| Batch output / 1M | - | $0.25 |
| Long-context rates above | - | 272,000 tokens |
| Context window | 1,000,000 | 1,050,000 |
| Max output | 393,216 | 128,000 |
| Release date | ||
| Weights | Open | Closed |
| License | MIT | - |
| API model id | deepseek-flash | gpt-6-luna |
| AI Gateway id | deepseek/deepseek-v4.1-flash-1017 | openai/gpt-6-luna |
| Last verified |
Prices in USD per 1M tokens at each provider's standard first-party rate. A dash means the provider does not bill that item separately or no primary page states it.
What each costs in practice
The same three workloads every model page uses, worked from each model's standard list rates. Swap in your own token counts with the math on each model's page.
| Workload | DeepSeek V4.1 Flash | GPT-6 Luna |
|---|---|---|
| One agent session1M input tokens and 100K output tokens, no caching. | $0.42 | $0.15 |
| A chat app10,000 requests a day at 2K input and 500 output tokens each. | $12.00$360.00 per 30-day month | $4.50$135.00 per 30-day month |
| The same session at a 90% cache hit90% of the input is read from the prompt cache. The one-time cache write premium is not included. | $0.1554 | $0.069 |
Show the math
DeepSeek V4.1 Flash
- One agent sessionInput: 1M x $0.30 = $0.30Output: 0.1M x $1.20 = $0.12
- A chat appInput: 20M x $0.30 = $6.00Output: 5M x $1.20 = $6.00
- The same session at a 90% cache hitCached input: 0.9M x $0.006 = $0.0054Uncached input: 0.1M x $0.30 = $0.03Output: 0.1M x $1.20 = $0.12
GPT-6 Luna
- One agent sessionInput: 1M x $0.10 = $0.10Output: 0.1M x $0.50 = $0.05
- A chat appInput: 20M x $0.10 = $2.00Output: 5M x $0.50 = $2.50
- The same session at a 90% cache hitCached input: 0.9M x $0.01 = $0.009Uncached input: 0.1M x $0.10 = $0.01Output: 0.1M x $0.50 = $0.05
Benchmarks under the same setting
No board in the benchmark directory lists both DeepSeek V4.1 Flash and GPT-6 Luna under the same setting, so there is no like-for-like score to show here.
Set them up in your tools
Step-by-step guides whose official docs list DeepSeek V4.1 Flash or GPT-6 Luna by model id.
- Use DeepSeek in AiderLists DeepSeek V4.1 Flash
- Use DeepSeek in Claude CodeLists DeepSeek V4.1 Flash
- Use DeepSeek in ClineLists DeepSeek V4.1 Flash
- Use DeepSeek in Codex CLILists DeepSeek V4.1 Flash
- Use DeepSeek in ContinueLists DeepSeek V4.1 Flash
- Use DeepSeek in GitHub CopilotLists DeepSeek V4.1 Flash
- Use DeepSeek in GooseLists DeepSeek V4.1 Flash
- Use DeepSeek in Kilo CodeLists DeepSeek V4.1 Flash
- Use DeepSeek in OpenCodeLists DeepSeek V4.1 Flash
- Use DeepSeek in Roo CodeLists DeepSeek V4.1 Flash
- Use DeepSeek in ZedLists DeepSeek V4.1 Flash
- Use OpenAI in AiderLists GPT-6 Luna
- Use OpenAI in ClineLists GPT-6 Luna
- Use OpenAI in Codex CLILists GPT-6 Luna
- Use OpenAI in ContinueLists GPT-6 Luna
- Use OpenAI in GooseLists GPT-6 Luna
- Use OpenAI in OpenCodeLists GPT-6 Luna
- Use OpenAI in Roo CodeLists GPT-6 Luna
- Use OpenAI in ZedLists GPT-6 Luna
Model pages
FAQ
How do DeepSeek V4.1 Flash and GPT-6 Luna compare on price?
On list price, DeepSeek V4.1 Flash charges 3x GPT-6 Luna's input price ($0.30 vs $0.10 per 1M tokens), and DeepSeek V4.1 Flash charges 2.4x GPT-6 Luna's output price ($1.20 vs $0.50 per 1M tokens). For one agent session of 1M input and 100K output tokens with no caching, that is $0.42 on DeepSeek V4.1 Flash and $0.15 on GPT-6 Luna. Prices are each provider's first-party list rates, verified October 17, 2026 and October 17, 2026.
What are the context windows of DeepSeek V4.1 Flash and GPT-6 Luna?
DeepSeek V4.1 Flash has a 1,000,000-token context window and GPT-6 Luna 1,050,000 tokens; max output is 393,216 and 128,000 tokens per response.
Are DeepSeek V4.1 Flash and GPT-6 Luna open weights?
DeepSeek V4.1 Flash's weights are published at huggingface.co under the MIT. GPT-6 Luna is closed-weights and is called through OpenAI's API as gpt-6-luna.
More comparisons
- Claude Haiku 5.5 vs DeepSeek V4.1 FlashOpen weights vs closed
- Claude Haiku 5.5 vs GPT-6 LunaSimilar price, same tier
- DeepSeek V4.1 Flash vs GLM-5.3-FlashSimilar price, same tier
- GLM-5.3-Flash vs GPT-6 LunaSimilar price, same tier
- DeepSeek V4.1 Flash vs Qwen3.8-FlashSimilar price, same tier
- GPT-6 Luna vs Qwen3.8-FlashSimilar price, same tier
- DeepSeek V4.1 Flash vs Gemini 3.5 Flash-LiteSimilar price, same tier
- GPT-5.6 Luna vs GPT-6 LunaSame provider, successor
Sources
DeepSeek V4.1 Flash verified from api-docs.deepseek.com; GPT-6 Luna verified from developers.openai.com. This page is as current as the older of the two: .
- https://api-docs.deepseek.com/quick_start/pricing
- https://developers.openai.com/api/docs/pricing
- https://api-docs.deepseek.com/updates
- https://api-docs.deepseek.com/news/news260910
- https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash
- https://vercel.com/ai-gateway/models/deepseek-v4-pro
- https://developers.openai.com/api/docs/models/gpt-6-luna
- https://developers.openai.com/api/docs/changelog
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