DeepSeek V4.1 Flash
deepseek/deepseek-v4.1-flash
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DeepSeek V4.1 Flash

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deepseek/deepseek-v4.1-flashReleased Sep 10, 202610% off

DeepSeek's newest Flash model and the first of its V4.1 architecture series: natively multimodal, a 1M-token context window, up to 384K output tokens, and a thinking mode that can be turned off or dialled between low, high and max. DeepSeek reports it has surpassed V4 Pro on capability, speed and end-to-end latency, and it is also the model now serving the retired V4 Flash model names.

Modalities
TextImageText
Context
1M
Max output
384K
Price / 1M tokens
$ 0.30$ 0.27in$ 1.08out
StreamingTool callingJSON outputImage inputThinking mode · can be turned off

What this model is good at

What the vendor positions it for, and which of our models to reach for instead.

VendorDeepSeek describes it as the smallest model in a new architecture series designed for a higher capability ceiling, faster inference and greater throughput, and says it has surpassed V4 Pro across performance, speed and total elapsed time.source

Best for
  • Terminal and coding agents · The vendor reports Terminal-Bench 2.1 at 90.6 and DeepSWE 1.1 at 74.2.source

  • Agents that read screenshots and charts · Image understanding is native to this model rather than a separate experimental variant, and one request can carry up to 600 images.source

  • Hard knowledge and research · The vendor reports GPQA Diamond at 90.9, and Humanity's Last Exam at 63.9 when tools are allowed.source

  • High-throughput production traffic · DeepSeek documents a concurrency limit of 2500 for the flash tier, five times the V4 Pro limit.source

Neighbouring models
  • deepseek/deepseek-v4-propredecessor —V4 Pro is still a distinct model until 2026-09-14 12:00 Beijing time; after that DeepSeek routes deepseek-v4-pro requests to V4.1 Flash.source
  • deepseek/deepseek-v4-flashpredecessor —V4 Flash and V4 Flash Vision Exp are retired upstream; those model ids are kept as compatibility aliases and are served by V4.1 Flash.source
Compare them side by side →

Pricing and billing

Billed per token. Cached input is charged at the cache-read rate.

Price / 1M tokensYou pay
Input$ 0.30$ 0.27
Output$ 1.20$ 1.08
Cache read$ 0.0060$ 0.0054
Cache write$ 0.30$ 0.27
Estimate a request
$ 0.0049
Estimated cost per request
10.0K × $ 0.27
+ 2.0K × $ 1.08
≈ $ 4.86 per 1,000 requests

Capabilities and limits

What CrossModel guarantees across every route this model can take right now.

Context window
1.0M tokens
Max output
384.0K tokens
Input / output modalities
Text + Image → Text
Streaming
Supported
Tool calling
Supported
Structured output (JSON)
Supported
Image input
Supported
Thinking mode
Supported· can be turned off
Reasoning effort
low · medium · high · xhigh · max
Available endpoints
/v1/chat/completions · /v1/responses · /v1/messages

Published benchmarks

Scores the vendor reported, with the evaluation setup each one came from.

Agentic coding
  • Terminal-Bench 2.1
    pass_rate·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测。来源页这一轮未重述 harness 与采样设置(V4 系列此前统一用 DeepSeek Harness 极简模式、max 档位),所以 settings 留空;不可与第三方独立运行的同名成绩直接互换。

    90.6%
  • Terminal-Bench 4.0
    pass_rate·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测。来源页同时给出 Terminal-Bench 3.0 的 30.0;不同版本是不同身份,此处只录最新一版。来源页未披露该项的评测设置。

    31.2%
Agentic work
  • Agents' Last Exam
    score·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测;来源页未披露该项的评测设置。

    31.8%
  • AutomationBench
    score·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测。来源页写作 Automation-Bench 且未标注 Public 划分,所以不用 AutomationBench (Public) 那个身份;来源页未披露该项的评测设置。

    54.8%
Coding
  • DeepSWE 1.1
    resolved_rate·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测;来源页未披露该项的评测设置。

    74.2%
  • NL2Repo
    score·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测。来源页写作 NL2Repo-Bench,沿用目录既有的 NL2Repo 身份;来源页只给出百分数,未说明具体 metric,保守记为 score。

    65.4%
Cybersecurity
  • CyberGym
    score·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测;来源页未披露该项的评测设置。

    88.1%
Math reasoning
  • MathArena Apex
    score·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测;来源页只给出数值,未说明具体 metric,保守记为 score。

    65.6%
Multimodal reasoning
  • Chartography (with tools)
    score·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测,来源页标注 w/tools;与不带工具的 Chartography 不是同一身份,不要混用。来源页未披露具体工具集合。

    78.9%
Reasoning
  • Humanity's Last Exam
    accuracy·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测。来源页另给出 39.1,但注明那只在 HLE 的纯文本子集上测试,所以这里记录全集成绩;来源页未披露该项的评测设置。

    36.8%
  • Humanity's Last Exam (with tools)
    accuracy·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测。来源页只标注 w/tools,未披露具体工具集合,所以 settings 里不写 tools。

    63.9%
Scientific reasoning
  • GPQA Diamond
    accuracy·DeepSeek · 2026-09-10setup not fully disclosed

    厂商自测;来源页未披露该项的评测设置。

    90.9%

Vendor-reported numbers, not CrossModel measurements. Scores are only comparable when the benchmark version, metric and evaluation setup match, so nothing here is averaged or ranked.

Use it in your tools

Point the base URL at CrossModel and paste this model ID — every tool below has a setup guide.

See all integration guides →

Frequently asked questions

What is DeepSeek V4.1 Flash?
DeepSeek V4.1 Flash is available on CrossModel as deepseek/deepseek-v4.1-flash. It has a 1M-token context window and can return up to 384K tokens per request.
How much does DeepSeek V4.1 Flash cost?
Currently $ 0.27 per 1M input tokens and $ 1.08 per 1M output tokens. Cached input is billed at $ 0.0054 per 1M.
Does DeepSeek V4.1 Flash support tool calling and structured output?
Tool calling: Supported · Structured output (JSON): Supported · Image input: Supported · Streaming: Supported · Thinking mode: Supported
Which endpoint do I call?
For text models, OpenAI Chat Completions (/v1/chat/completions), OpenAI Responses (/v1/responses) and Anthropic Messages (/v1/messages) all work — pick whichever your SDK already speaks.
Can I try it without writing code?
Yes. Sign in and open the Playground on this page to chat with the model directly — no API key needed. Usage is billed from your wallet at the normal rate.

Chat first, integrate later

Chat first, then wire it in once you like the answers.