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DeepSeek V4 Flash 0423 vs Qwen3.5 397B A17B

Updated October 21, 2026. 43 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace DeepSeek V4 Flash 0423 Replace Qwen3.5 397B A17B
DeepSeek V4 Flash 0423DeepSeek
Coding
54.6
Overall
24.4
Output $/M
$0.182
14
Qwen3.5 397B A17BQwen
Coding
28.6
Overall
21.4
Output $/M
$2.34
29
vs boards won of 43 shared

Decision reading

Pick DeepSeek V4 Flash 0423 for coding: it scores 54.6 on the Vibe Coding Index against 28.6 for Qwen3.5 397B A17B.

Pick Qwen3.5 397B A17B when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.

Model ADeepSeek V4 Flash 0423DeepSeek54.6/1001 independent benchmarkNo cost per solved taskModel BQwen3.5 397B A17BQwen28.6/1001 independent benchmarkNo cost per solved task
Shared results
43
DeepSeek V4 Flash 0423 only
5
Qwen3.5 397B A17B only
22
Like-for-like categories
7 of 9

Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
DeepSeek V4 Flash 0423 54.6 from 1 benchmark, Qwen3.5 397B A17B 28.6 from 1 benchmark.
Widest category
Coding, 14.7 points apart on average over 6 shared benchmarks.
Widest single gap
LMArena WebDev: React: DeepSeek V4 Flash 0423 1585 against Qwen3.5 397B A17B 1388, 32.9 points apart on a 0 to 100 scale.
Output price
DeepSeek V4 Flash 0423 $0.182 against Qwen3.5 397B A17B $2.34 per million output tokens, 12.9x apart.
Context window
DeepSeek V4 Flash 0423 takes 1.05M tokens, Qwen3.5 397B A17B 262K.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryDeepSeek V4 Flash 0423BarsQwen3.5 397B A17BTies
Coding42
Intelligence11
Reasoning03
Math02
Knowledge04
Web design61
General316
All shared boards1429
CodingLike-for-likeFour of these boards feed the Vibe Coding Index42
Coding benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
LMArena WebDev15821400DeepSeek V4 Flash 0423
AA Coding Index52.0Not measuredOnly DeepSeek V4 Flash 0423 measured
SciCodeNot measured44.8%Only Qwen3.5 397B A17B measured
Terminal-Bench Hard (Artificial Analysis run)Not measured40.9%Only Qwen3.5 397B A17B measured
WeirdML45.6%Not measuredOnly DeepSeek V4 Flash 0423 measured
ALE-Bench678.2621.9DeepSeek V4 Flash 0423
LMArena Text: coding14571464Qwen3.5 397B A17B
LMArena Text: software and IT14531463Qwen3.5 397B A17B
LMArena WebDev: React15851388DeepSeek V4 Flash 0423
LMArena WebDev: HTML15581410DeepSeek V4 Flash 0423
Neither model has a result on the other 28 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index11
Intelligence benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
AA Intelligence Index24.421.4DeepSeek V4 Flash 0423
Epoch Capabilities Index146.1146.8Qwen3.5 397B A17B
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
Agentic work benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
AA Agentic Index26.3Not measuredOnly DeepSeek V4 Flash 0423 measured
τ²-Bench TelecomNot measured95.6%Only Qwen3.5 397B A17B measured
APEX-AgentsNot measured24.9%Only Qwen3.5 397B A17B measured
Neither model has a result on the other 36 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index03
Reasoning benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
GPQA Diamond (Artificial Analysis run)Not measured89.3%Only Qwen3.5 397B A17B measured
Humanity's Last Exam (Artificial Analysis run)Not measured29.0%Only Qwen3.5 397B A17B measured
GPQA Diamond (Epoch AI run)Not measured86.4%Only Qwen3.5 397B A17B measured
SimpleBench46.3%Not measuredOnly DeepSeek V4 Flash 0423 measured
Mystery game puzzlesNot measured18.0%Only Qwen3.5 397B A17B measured
LMArena Text: hard prompts14441448Qwen3.5 397B A17B
LMArena Text: expert14411462Qwen3.5 397B A17B
LMArena Text: hard prompts in English14491450Qwen3.5 397B A17B
LMArena Vision: diagramsNot measured1277Only Qwen3.5 397B A17B measured
LMArena Vision: homeworkNot measured1292Only Qwen3.5 397B A17B measured
Neither model has a result on the other 11 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index02
Math benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
OTIS Mock AIMENot measured88.9%Only Qwen3.5 397B A17B measured
FrontierMath, tiers 1 to 3Not measured31.2%Only Qwen3.5 397B A17B measured
LMArena Text: math14261453Qwen3.5 397B A17B
LMArena Text: mathematical work14321454Qwen3.5 397B A17B
Neither model has a result on the other 9 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index04
Knowledge benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
LMArena Text: science14461457Qwen3.5 397B A17B
LMArena Text: medicine and healthcare14481455Qwen3.5 397B A17B
LMArena Text: legal and government14391441Qwen3.5 397B A17B
LMArena Text: business and finance14251435Qwen3.5 397B A17B
Neither model has a result on the other 13 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index61
Web design benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
Design Arena: websites12081191DeepSeek V4 Flash 0423
Design Arena: UI components11641163DeepSeek V4 Flash 0423
Design Arena: game dev11971141DeepSeek V4 Flash 0423
Design Arena: data viz11271175Qwen3.5 397B A17B
Design Arena: 3D11891161DeepSeek V4 Flash 0423
Design Arena: all code categories12051180DeepSeek V4 Flash 0423
Design Arena: SVG11551139DeepSeek V4 Flash 0423
Design Arena: ASCII art1109Not measuredOnly DeepSeek V4 Flash 0423 measured
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index316
General benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
IFBenchNot measured78.8%Only Qwen3.5 397B A17B measured
Long context reasoning (AA-LCR)Not measured77.3%Only Qwen3.5 397B A17B measured
DTBench86.4%87.5%Qwen3.5 397B A17B
LMCA35.9%37.9%Qwen3.5 397B A17B
LMArena Text14321437Qwen3.5 397B A17B
LMArena Text: instruction following14211424Qwen3.5 397B A17B
LMArena Text: creative writing14031402DeepSeek V4 Flash 0423
LMArena VisionNot measured1262Only Qwen3.5 397B A17B measured
LMArena Text: English14411443Qwen3.5 397B A17B
LMArena Text: non-English14191430Qwen3.5 397B A17B
LMArena Text: Chinese14631498Qwen3.5 397B A17B
LMArena Text: German14191445Qwen3.5 397B A17B
LMArena Text: Japanese13891429Qwen3.5 397B A17B
LMArena Text: Korean13831384Qwen3.5 397B A17B
LMArena Text: French14391462Qwen3.5 397B A17B
LMArena Text: Spanish14361441Qwen3.5 397B A17B
LMArena Text: Russian14271430Qwen3.5 397B A17B
LMArena Text: Polish14361447Qwen3.5 397B A17B
LMArena Text: multi-turn14491446DeepSeek V4 Flash 0423
LMArena Text: longer queries14341441Qwen3.5 397B A17B
LMArena Text: writing and language14101415Qwen3.5 397B A17B
LMArena Text: entertainment and media14001399DeepSeek V4 Flash 0423
LMArena Vision: EnglishNot measured1268Only Qwen3.5 397B A17B measured
LMArena Vision: ChineseNot measured1314Only Qwen3.5 397B A17B measured
LMArena Vision: reading textNot measured1271Only Qwen3.5 397B A17B measured
LMArena Vision: humorNot measured1262Only Qwen3.5 397B A17B measured
LMArena Vision: captioningNot measured1230Only Qwen3.5 397B A17B measured
LMArena Vision: recognizing thingsNot measured1265Only Qwen3.5 397B A17B measured
LMArena Vision: creative writingNot measured1260Only Qwen3.5 397B A17B measured
Neither model has a result on the other 17 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
BenchmarkDeepSeek V4 Flash 0423Qwen3.5 397B A17BLeader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

DeepSeek V4 Flash 0423$0.0002Fits in one request
Qwen3.5 397B A17B$0.0016Fits in one request

DeepSeek V4 Flash 0423 costs less

Repository review

50K input + 3K output tokens

DeepSeek V4 Flash 0423$0.0051Fits in one request
Qwen3.5 397B A17B$0.027Fits in one request

DeepSeek V4 Flash 0423 costs less

Agent loop

200K input + 10K output tokens

DeepSeek V4 Flash 0423$0.020Fits in one request
Qwen3.5 397B A17B$0.101Fits in one request

DeepSeek V4 Flash 0423 costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of DeepSeek V4 Flash 0423 and Qwen3.5 397B A17B
SpecificationDeepSeek V4 Flash 0423Qwen3.5 397B A17B
MakerDeepSeekQwen
WeightsOpen weightsOpen weights
ReleasedApril 24, 2026February 16, 2026
Context window1.05M262K
Input $/Mtok$0.091$0.39
Output $/Mtok$0.182$2.34
Coding index54.628.6
Independent measurements behind it11
Cost per solved taskNot computableNot computable
SourceOpenRouter listingOpenRouter listing

Questions

Is DeepSeek V4 Flash 0423 better than Qwen3.5 397B A17B for coding?

Pick DeepSeek V4 Flash 0423 for coding: it scores 54.6 on the Vibe Coding Index against 28.6 for Qwen3.5 397B A17B. Pick Qwen3.5 397B A17B when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.

Which is cheaper, DeepSeek V4 Flash 0423 or Qwen3.5 397B A17B?

DeepSeek V4 Flash 0423 costs $0.091 per million input tokens and $0.182 per million output tokens; Qwen3.5 397B A17B costs $0.39 and $2.34. Cost per solved task is known for neither of them.

Which has the bigger context window, DeepSeek V4 Flash 0423 or Qwen3.5 397B A17B?

DeepSeek V4 Flash 0423, with 1.05M tokens against 262K.

How many benchmarks is the DeepSeek V4 Flash 0423 vs Qwen3.5 397B A17B comparison based on?

43 benchmarks have a result for both models as of October 21, 2026. DeepSeek V4 Flash 0423's coding index rests on 1 independent benchmark and Qwen3.5 397B A17B's on 1. Where only one model has a result, the page says so instead of naming a winner.

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