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Comparison · 2 models · Updated Oct 4, 2026

DeepSeek V4.1 Flash vs GPT-6 Luna

GPT-6 Luna comes out ahead, 78 to 72 on our weighted score, and it is the cheaper option too.

  1. DeepSeek

    DeepSeek V4.1 Flash

    Released Sep 10, 2026

    72/100
    • ECI155.0
    • Price$0.15 / $0.60
    • Context1M
    Full specs Remove DeepSeek V4.1 Flash
  2. Our pick

    OpenAI

    GPT-6 Luna

    Released Sep 22, 2026

    78/100
    • ECI—
    • Price$0.10 / $0.50
    • Context1.05M
    Full specs Remove GPT-6 Luna

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GPT-6 Luna is our pick

GPT-6 Luna is the better all-round choice, scoring 78/100 against DeepSeek V4.1 Flash (72). It leads on price and inputs & features. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceGPT-6 LunaGPT-6 Luna $0.20 · DeepSeek V4.1 Flash $0.263 per 1M tokens (3:1 blend)
  • Longest contextGPT-6 LunaGPT-6 Luna 1,050,000 · DeepSeek V4.1 Flash 1,000,000 tokens
  • Widest inputsGPT-6 LunaDeepSeek V4.1 Flash: Text, Images · GPT-6 Luna: Text, Images, PDFs
  • Self-hostingDeepSeek V4.1 FlashPublishes downloadable weights (MIT)
How the score is built
MeasureWeightDeepSeek V4.1 FlashGPT-6 Luna
Price50%7783
Inputs & features30%7080
Context window20%6061
Overall100%72/10078/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

DeepSeek V4.1 Flash vs GPT-6 Luna specifications side by side
SpecificationDeepSeek V4.1 FlashDeepSeekGPT-6 LunaOpenAI
Capability
Capabilities Index (ECI)155.0—
ECI rank#29 of 148—
GPQA DiamondGraduate-level science questions—90.5%
FrontierMath Tiers 1–3Research-level mathematics—79.0%
OTIS Mock AIME 2024–2025Competition mathematics—98.9%
SimpleQA VerifiedShort factual questions—41.4%
Price per million tokens
Input$0.15$0.10 (best)
Output$0.60$0.50 (best)
Cached input$0.003 (best)$0.01
Blended (3:1)$0.263$0.20 (best)
Long-context rateSame rateOver 272K: $0.20 / $0.75
Price sourceOfficial DeepSeek APIOfficial OpenAI API
Limits
Context window1,000,000 tokens1,050,000 tokens (best)
Max output384,000 tokens (best)128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoYes
AudioNoNo
VideoNoNo
ReasoningYeslow · high · maxYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsOpenMITProprietary
API model IDdeepseek-flashgpt-6-luna
API providers50 (best)24
ReleasedSep 10, 2026Sep 22, 2026
Knowledge cutoffMay 2025May 18, 2026
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • DeepSeek V4.1 Flash$2.70
  • GPT-6 Luna$2.00
04 — Questions

Which should you choose?

Which is better: DeepSeek V4.1 Flash or GPT-6 Luna?

GPT-6 Luna is the better all-round choice, scoring 78/100 against DeepSeek V4.1 Flash (72). It leads on price and inputs & features. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, DeepSeek V4.1 Flash or GPT-6 Luna?

GPT-6 Luna is cheaper at $0.10 input / $0.50 output per million tokens (official OpenAI API price). DeepSeek V4.1 Flash costs $0.15 input / $0.60 output per million tokens (official DeepSeek API price). At a typical mix of three input tokens to one output token, that is $0.20 per million tokens for GPT-6 Luna versus $0.263 for DeepSeek V4.1 Flash (1.3× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. DeepSeek V4.1 Flash has an ECI of 155.0 and GPT-6 Luna has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for DeepSeek V4.1 Flash and GPT-6 Luna yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-6 Luna has the largest context window at 1,050,000 tokens, against 1,000,000 for DeepSeek V4.1 Flash. Maximum output per response: DeepSeek V4.1 Flash up to 384,000, GPT-6 Luna up to 128,000 tokens.

Which can read images, PDFs, audio or video?

DeepSeek V4.1 Flash accepts text and images; GPT-6 Luna accepts text, images and PDFs. GPT-6 Luna handles the widest range of inputs.

Are any of these open source?

DeepSeek V4.1 Flash publishes its weights (MIT) and can be self-hosted; GPT-6 Luna is proprietary.

Which is newer?

GPT-6 Luna is the newest, released Sep 22, 2026. DeepSeek V4.1 Flash came out Sep 10, 2026. Knowledge cutoff: DeepSeek V4.1 Flash May 2025, GPT-6 Luna May 18, 2026.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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