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DeepSeek V4 Pro 0813 vs Qwen3.5-Flash

Updated October 21, 2026. 47 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace DeepSeek V4 Pro 0813 Replace Qwen3.5-Flash
DeepSeek V4 Pro 0813DeepSeek
Coding
54.6
Overall
36.0
Output $/M
$1.98
46
Qwen3.5-FlashQwen
Coding
6.2
Overall
No data
Output $/M
$0.26
1
vs boards won of 47 shared

Decision reading

Pick DeepSeek V4 Pro 0813 for coding: it scores 54.6 on the Vibe Coding Index against 6.2 for Qwen3.5-Flash.

Pick Qwen3.5-Flash when output tokens cost 7.6x less, or when the benchmark that matters is LegalBench (Vals AI), where it leads.

Model ADeepSeek V4 Pro 0813DeepSeek54.6/1001 independent benchmark$0.10 per solved taskModel BQwen3.5-FlashQwen6.2/1001 independent benchmark$0.40 per solved task
Shared results
47
DeepSeek V4 Pro 0813 only
31
Qwen3.5-Flash only
8
Like-for-like categories
6 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 Pro 0813 54.6 from 1 benchmark, Qwen3.5-Flash 6.2 from 1 benchmark.
Widest category
Coding, 30.7 points apart on average over 8 shared benchmarks.
Widest single gap
LMArena WebDev: React: DeepSeek V4 Pro 0813 1588 against Qwen3.5-Flash 1229, 59.8 points apart on a 0 to 100 scale.
Output price
DeepSeek V4 Pro 0813 $1.98 against Qwen3.5-Flash $0.26 per million output tokens, 7.6x apart.
Context window
DeepSeek V4 Pro 0813 takes 1.05M tokens, Qwen3.5-Flash 1M.

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 Pro 0813BarsQwen3.5-FlashTies
Coding80
Intelligence10
Reasoning70
Math40
Knowledge91
General170
All shared boards461
CodingLike-for-likeFour of these boards feed the Vibe Coding Index80
Coding benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
LMArena WebDev15821244DeepSeek V4 Pro 0813
AA Coding Index68.8Not measuredOnly DeepSeek V4 Pro 0813 measured
LiveCodeBench (Vals AI)87.5%83.3%DeepSeek V4 Pro 0813
SWE-bench Verified (Vals AI)96.4%64.4%DeepSeek V4 Pro 0813
Terminal-Bench 4 (Vals AI)14.1%Not measuredOnly DeepSeek V4 Pro 0813 measured
Vibe Code Bench (Vals AI)82.3%Not measuredOnly DeepSeek V4 Pro 0813 measured
Code migration (Vals AI)41.5%Not measuredOnly DeepSeek V4 Pro 0813 measured
ProgramBench (Vals AI)0.0%Not measuredOnly DeepSeek V4 Pro 0813 measured
IOI (Vals AI)51.6%Not measuredOnly DeepSeek V4 Pro 0813 measured
Terminal-Bench 2.1 (Vals AI)54.7%Not measuredOnly DeepSeek V4 Pro 0813 measured
Vibe Code Bench 1-100 (Vals AI)17.5%Not measuredOnly DeepSeek V4 Pro 0813 measured
SkillsBench (Vals AI)53.8%Not measuredOnly DeepSeek V4 Pro 0813 measured
CyberBench (Vals AI)72.9%Not measuredOnly DeepSeek V4 Pro 0813 measured
SciCode51.0%Not measuredOnly DeepSeek V4 Pro 0813 measured
FrontierCode28.5%Not measuredOnly DeepSeek V4 Pro 0813 measured
WeirdML66.2%Not measuredOnly DeepSeek V4 Pro 0813 measured
ALE-Bench1403.2265.9DeepSeek V4 Pro 0813
LMArena Text: coding14691412DeepSeek V4 Pro 0813
LMArena Text: software and IT14621416DeepSeek V4 Pro 0813
LMArena WebDev: React15881229DeepSeek V4 Pro 0813
LMArena WebDev: HTML15661291DeepSeek V4 Pro 0813
Neither model has a result on the other 17 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
Intelligence benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
AA Intelligence Index36.0Not measuredOnly DeepSeek V4 Pro 0813 measured
Epoch Capabilities Index155.6143.5DeepSeek V4 Pro 0813
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
Agentic work benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
AA Agentic Index41.3Not measuredOnly DeepSeek V4 Pro 0813 measured
SREBench (Vals AI)1.9%Not measuredOnly DeepSeek V4 Pro 0813 measured
Finance Agent (Vals AI)50.4%Not measuredOnly DeepSeek V4 Pro 0813 measured
Tax Agent Bench (Vals AI)26.8%Not measuredOnly DeepSeek V4 Pro 0813 measured
Legal Research Bench (Vals AI)40.9%Not measuredOnly DeepSeek V4 Pro 0813 measured
Harvey's Legal Agent Benchmark (Vals AI)10.8%Not measuredOnly DeepSeek V4 Pro 0813 measured
Excel Modeling Benchmark (Vals AI)52.8%Not measuredOnly DeepSeek V4 Pro 0813 measured
Terminal-Bench-Science (Vals AI)4.3%Not measuredOnly DeepSeek V4 Pro 0813 measured
APEX-Agents47.3%Not measuredOnly DeepSeek V4 Pro 0813 measured
Neither model has a result on the other 30 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index70
Reasoning benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
GPQA Diamond92.4%82.8%DeepSeek V4 Pro 0813
MMMU Pro (Vals AI)Not measured81.9%Only Qwen3.5-Flash measured
GPQA Diamond (Artificial Analysis run)92.8%Not measuredOnly DeepSeek V4 Pro 0813 measured
Humanity's Last Exam (Artificial Analysis run)41.0%Not measuredOnly DeepSeek V4 Pro 0813 measured
GPQA Diamond (Epoch AI run)91.7%82.3%DeepSeek V4 Pro 0813
ARC-AGI90.5%Not measuredOnly DeepSeek V4 Pro 0813 measured
ARC-AGI-261.3%Not measuredOnly DeepSeek V4 Pro 0813 measured
Chess puzzles46.0%14.0%DeepSeek V4 Pro 0813
Mystery game puzzles43.0%20.0%DeepSeek V4 Pro 0813
LMArena Text: hard prompts14581403DeepSeek V4 Pro 0813
LMArena Text: expert14591407DeepSeek V4 Pro 0813
LMArena Text: hard prompts in English14631409DeepSeek V4 Pro 0813
Neither model has a result on the other 9 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index40
Math benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
AIMENot measured92.5%Only Qwen3.5-Flash measured
OTIS Mock AIME98.6%84.4%DeepSeek V4 Pro 0813
FrontierMath, tiers 1 to 364.6%18.2%DeepSeek V4 Pro 0813
FrontierMath, tier 426.8%Not measuredOnly DeepSeek V4 Pro 0813 measured
ProofBench50.0%Not measuredOnly DeepSeek V4 Pro 0813 measured
LMArena Text: math14411407DeepSeek V4 Pro 0813
LMArena Text: mathematical work14431413DeepSeek V4 Pro 0813
Neither model has a result on the other 6 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index91
Knowledge benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
MMLU Pro87.0%84.1%DeepSeek V4 Pro 0813
LegalBench (Vals AI)82.4%84.3%Qwen3.5-Flash
CaseLaw (Vals AI)Not measured56.0%Only Qwen3.5-Flash measured
CorpFin (Vals AI)65.4%63.6%DeepSeek V4 Pro 0813
TaxEval (Vals AI)73.1%72.2%DeepSeek V4 Pro 0813
MortgageTax (Vals AI)Not measured67.4%Only Qwen3.5-Flash measured
MedCode (Vals AI)42.5%33.0%DeepSeek V4 Pro 0813
SimpleQA Verified52.9%20.3%DeepSeek V4 Pro 0813
LMArena Text: science14571415DeepSeek V4 Pro 0813
LMArena Text: medicine and healthcare14461407DeepSeek V4 Pro 0813
LMArena Text: legal and government14591398DeepSeek V4 Pro 0813
LMArena Text: business and finance14421394DeepSeek V4 Pro 0813
Neither model has a result on the other 5 boards here
Web designNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Web design benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
Neither model has a result on 9 boards here
GeneralLike-for-likePublic boards, shown as published, kept out of the index170
General benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
Vals Index53.0%Not measuredOnly DeepSeek V4 Pro 0813 measured
SAGE (Vals AI)Not measured42.5%Only Qwen3.5-Flash measured
MedScribe (Vals AI)80.2%70.6%DeepSeek V4 Pro 0813
Long context reasoning (AA-LCR)80.3%Not measuredOnly DeepSeek V4 Pro 0813 measured
DTBench93.9%82.9%DeepSeek V4 Pro 0813
LMCA45.5%29.1%DeepSeek V4 Pro 0813
LMArena Text14461397DeepSeek V4 Pro 0813
LMArena Text: instruction following14481374DeepSeek V4 Pro 0813
LMArena Text: creative writing14391343DeepSeek V4 Pro 0813
LMArena Text: English14571404DeepSeek V4 Pro 0813
LMArena Text: non-English14311385DeepSeek V4 Pro 0813
LMArena Text: Chinese14811445DeepSeek V4 Pro 0813
LMArena Text: GermanNot measured1390Only Qwen3.5-Flash measured
LMArena Text: JapaneseNot measured1369Only Qwen3.5-Flash measured
LMArena Text: Korean14491344DeepSeek V4 Pro 0813
LMArena Text: French14461413DeepSeek V4 Pro 0813
LMArena Text: Spanish14351400DeepSeek V4 Pro 0813
LMArena Text: Russian14481380DeepSeek V4 Pro 0813
LMArena Text: PolishNot measured1376Only Qwen3.5-Flash measured
LMArena Text: multi-turn14541393DeepSeek V4 Pro 0813
LMArena Text: longer queries14581392DeepSeek V4 Pro 0813
LMArena Text: writing and language14431369DeepSeek V4 Pro 0813
LMArena Text: entertainment and media14241347DeepSeek V4 Pro 0813
Neither model has a result on the other 23 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for DeepSeek V4 Pro 0813 and Qwen3.5-Flash
BenchmarkDeepSeek V4 Pro 0813Qwen3.5-FlashLeader
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 Pro 0813$0.0016Fits in one request
Qwen3.5-Flash$0.0002Fits in one request

Qwen3.5-Flash costs less

Repository review

50K input + 3K output tokens

DeepSeek V4 Pro 0813$0.039Fits in one request
Qwen3.5-Flash$0.0040Fits in one request

Qwen3.5-Flash costs less

Agent loop

200K input + 10K output tokens

DeepSeek V4 Pro 0813$0.152Fits in one request
Qwen3.5-Flash$0.016Fits in one request

Qwen3.5-Flash 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 Pro 0813 and Qwen3.5-Flash
SpecificationDeepSeek V4 Pro 0813Qwen3.5-Flash
MakerDeepSeekQwen
WeightsOpen weightsNo public weights listed
ReleasedAugust 12, 2026February 25, 2026
Context window1.05M1M
Input $/Mtok$0.66$0.065
Output $/Mtok$1.98$0.26
Coding index54.66.2
Independent measurements behind it11
Cost per solved task$0.10$0.40
SourceOpenRouter listingOpenRouter listing

Questions

Is DeepSeek V4 Pro 0813 better than Qwen3.5-Flash for coding?

Pick DeepSeek V4 Pro 0813 for coding: it scores 54.6 on the Vibe Coding Index against 6.2 for Qwen3.5-Flash. Pick Qwen3.5-Flash when output tokens cost 7.6x less, or when the benchmark that matters is LegalBench (Vals AI), where it leads.

Which is cheaper, DeepSeek V4 Pro 0813 or Qwen3.5-Flash?

DeepSeek V4 Pro 0813 costs $0.66 per million input tokens and $1.98 per million output tokens; Qwen3.5-Flash costs $0.065 and $0.26. Per solved SWE-bench Verified task, DeepSeek V4 Pro 0813 costs $0.10 and Qwen3.5-Flash $0.40.

Which has the bigger context window, DeepSeek V4 Pro 0813 or Qwen3.5-Flash?

DeepSeek V4 Pro 0813, with 1.05M tokens against 1M.

How many benchmarks is the DeepSeek V4 Pro 0813 vs Qwen3.5-Flash comparison based on?

47 benchmarks have a result for both models as of October 21, 2026. DeepSeek V4 Pro 0813's coding index rests on 1 independent benchmark and Qwen3.5-Flash's on 1. Where only one model has a result, the page says so instead of naming a winner.

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