> DeepSeek-V4.1-Flash is an open-weights AI model from DeepSeek, released 10 Sep 2026. Index score 165 (GPT-4 = 100), rank 31 of 229 ranked models. API price $0.015 in / $0.40 out per million tokens, 1.05M context.

[Models](https://themodelindex.org/models/) /[DeepSeek](https://themodelindex.org/labs/deepseek/)

# DeepSeek-V4.1-Flash

DeepSeek

Released 10 Sep 2026

Open

[Compare](https://themodelindex.org/compare/deepseek-v4-1-flash-vs-claude-opus-5-5/) [Run it yourself →](https://themodelindex.org/local/) [Announcement](https://api-docs.deepseek.com/news/news260910/)

165154–177

Index score

#31 · provisional, limited data

0/ 8

Core tests taken

0 of 6 areas · plus 4 anchor tests

−32

Versus the frontier at release

best then: GPT-6 Astra

$0.015/ $0.40

Price per million tokens

input / output, list price

1.05M

Context window

tokens it reads at once

## Where it sits · on the frontier

_Chart: Model Index score of every scored model since late 2022, with the best closed and best open model over time_

Claude Opus 4.6 reached this score 7 months earlier.

## Test results · by area · tick = best by any model

Show 3 anchor tests

Reasoning & knowledge

no evidence yet

GPQA Diamond

no result

Humanity's Last Exam

no result

Maths

evidence

FrontierMath T1-3

no result

Coding

no evidence yet

SWE-bench Verified

no result

Terminal-Bench

no result

Agents

evidence

APEX-Agents

no result

Novel problems

no evidence yet

ARC-AGI-2

no result

Long tasks

no evidence yet

METR time horizon

no result

Independent results from the Epoch AI benchmarking hub, best reasoning setting. The core tests are shown here; anchor tests also inform the score and can be shown above.

## What others say · rank on each leaderboard

The Model Index

independent tests, our method

#31

of 219 · 165

LMArena · Maths

maths questions in chat

#12

of 373 · 1502

LMArena · Coding

coding questions in chat

#22

of 383 · 1529

LMArena · Text

overall chat quality, judged by people

#37

of 388 · 1473

Artificial Analysis Intelligence Index

overall capability across ten evaluations

#20

of 207 · 39

Epoch Capabilities Index

overall capability from many benchmarks

#28

of 239 · 155

LMArena · Creative writing

creative writing

#53

of 386 · 1438

LMArena · WebDev

building web apps and front ends

#19

of 123 · 1620

Further left is better. Leaderboards measure different things: LMArena is people voting blind between two answers, the others are test scores. Click any row for the source.

## Best at · top three among current models

Not in the top three among current models on any category we track.

Where this model places in the top three of today's models, on category leaderboards and on our core tests.

## Where to use it · prices checked 1 Oct 2026

#### From the lab

DeepSeek Chat

app · subscription

↗

DeepSeek API

API

↗

#### API providers · 28 · per million tokens, in / out

O

OpenInference

$0.030 / $0.50 · fp4

cheapest

M

Morph

$0.053 / $0.43 · fp8

↗

S

Sail Research

$0.080 / $0.40 · fp4

↗

R

Relace

$0.027 / $0.60

↗

W

Wafer

$0.050 / $0.60

↗

D

DekaLLM

$0.12 / $0.40

↗

I

Io Net

$0.12 / $0.41 · fp8

↗

D

DeepInfra

$0.14 / $0.42 · fp8

↗

#### Run it yourself

🤗

Official weights

deepseek-ai/DeepSeek-V4.1-Flash

↗

Provider prices come from OpenRouter's live listing; going direct to a provider can differ. Subscriptions are the lab's own apps.

## Facts and sources

Released

10 Sep 2026

Announcement

[api-docs.deepseek.com ↗](https://api-docs.deepseek.com/news/news260910/)

Release entry

DeepSeek-V4.1-Flash

Scored as

DeepSeek V4.1 Flash

Artificial Analysis index

39 · max

Output speed

209 tokens/s

Hugging Face

[deepseek-ai/DeepSeek-V4.1-Flash ↗](https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash)

## DeepSeek releases · around this one

DeepSeek-V4-Pro

Open

13 AUG 2026

index 167

DeepSeek-V4-Flash-Vision-Exp

Open

21 AUG 2026

DeepSeek-V4.1-Flash

Open

10 SEP 2026

index 165

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Source: https://themodelindex.org/models/deepseek-v4-1-flash/ · The Model Index · data as of 2026-10-01