DeepSeek V4.1 Flash vs GPT-6 Luna
DeepSeek V4.1 Flash (2026) and GPT-6 Luna (2026) are frontier-tier reasoning models from DeepSeek and OpenAI. DeepSeek V4.1 Flash ships a 1M-token context window, while GPT-6 Luna ships a 1.05M-token context window. On Google-Proof Q&A, DeepSeek V4.1 Flash leads by 0.4 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
GPT-6 Luna is safer overall; choose DeepSeek V4.1 Flash when vision-heavy evaluation matters.
Decision scorecard
Local evidence first| Signal | DeepSeek V4.1 Flash | GPT-6 Luna |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | RAG, Agents, and Long context | Coding, RAG, and Agents |
| Context window | 1M | 1.05M |
| Cheapest output | $0.60/1M tokens | $0.50/1M tokens |
| Provider routes | 2 tracked | 4 tracked |
| Shared benchmarks | Google-Proof Q&A leader | 1 shared |
Decision tradeoffs
- DeepSeek V4.1 Flash holds a shared-benchmark lead on Google-Proof Q&A, ahead by 0.4 points.
- Local decision data tags DeepSeek V4.1 Flash for RAG, Agents, and Long context.
- GPT-6 Luna has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-6 Luna has the lower cheapest tracked output price at $0.50/1M tokens.
- GPT-6 Luna has broader tracked provider coverage for fallback and route flexibility.
- GPT-6 Luna uniquely exposes Code execution in local model data.
- Local decision data tags GPT-6 Luna for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
DeepSeek V4.1 Flash
$270
Cheapest tracked route/tier: DeepSeek Platform Off-peak
GPT-6 Luna
$205
Cheapest tracked route/tier: OpenAI API
Estimated monthly gap: $65.00. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GPT-6 Luna is $0.10/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- GPT-6 Luna adds Code execution in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- DeepSeek V4.1 Flash is $0.10/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Code execution before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-09-10 | 2026-09-22 |
| Context window | 1M | 1.05M |
| Parameters | 552B | — |
| Architecture | Mixture of Experts | - |
| License | MITOSI-approved | Proprietary |
| Openness | Open source | Proprietary |
| Weights | Available | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: permitted | Commercial use: conditional |
| Knowledge cutoff | - | 2026-05 |
Pricing and availability
| Pricing attribute | DeepSeek V4.1 Flash | GPT-6 Luna |
|---|---|---|
| Input price |
| $0.10/1M tokens |
| Output price |
| $0.50/1M tokens |
| Providers |
Capabilities
| Capability | DeepSeek V4.1 Flash | GPT-6 Luna |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | DeepSeek V4.1 Flash | GPT-6 Luna |
|---|---|---|
| Google-Proof Q&A | 90.9 | 90.5 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has DeepSeek V4.1 Flash at 90.9 and GPT-6 Luna at 90.5, with DeepSeek V4.1 Flash ahead by 0.4 points. The largest visible gap is 0.4 points on Google-Proof Q&A, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on code execution: GPT-6 Luna. Both models share vision, multimodal input, reasoning mode, and JSON / Tool use, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, DeepSeek V4.1 Flash lists tiered pricing: Off-peak is $0.15/1M input and $0.60/1M output; Peak is $0.30/1M input and $1.20/1M output, while GPT-6 Luna lists $0.10/1M input and $0.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-6 Luna lower by about $0.07 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 2 providers versus 4, so concentration risk also matters.
Choose DeepSeek V4.1 Flash when vision-heavy evaluation are central to the workload. Choose GPT-6 Luna when coding workflow support, larger context windows, and lower input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, DeepSeek V4.1 Flash or GPT-6 Luna?
GPT-6 Luna supports 1.05M tokens, while DeepSeek V4.1 Flash supports 1M tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, DeepSeek V4.1 Flash or GPT-6 Luna?
DeepSeek V4.1 Flash lists tiered pricing: Off-peak is $0.15/1M input and $0.60/1M output; Peak is $0.30/1M input and $1.20/1M output. GPT-6 Luna lists $0.10/1M input and $0.50/1M output tokens on the cheapest tracked provider. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.
Is DeepSeek V4.1 Flash or GPT-6 Luna open source?
DeepSeek V4.1 Flash is listed under MIT. GPT-6 Luna is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, DeepSeek V4.1 Flash or GPT-6 Luna?
Both DeepSeek V4.1 Flash and GPT-6 Luna expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, DeepSeek V4.1 Flash or GPT-6 Luna?
Both DeepSeek V4.1 Flash and GPT-6 Luna expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run DeepSeek V4.1 Flash and GPT-6 Luna?
DeepSeek V4.1 Flash is available on DeepSeek Platform and OpenRouter. GPT-6 Luna is available on OpenAI API, AWS Bedrock, Azure OpenAI, and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-10-16. Data sourced from public model cards and provider documentation.