Noometry

Model comparison

DeepSeek V4.1 Flash vs Qwen3.5-Flash

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 42.5 on the Noometry Index.

Last verified . 26 shared benchmarks.

DeepSeek V4.1 Flash DeepSeek

52.8

Rank #38 Confirmed

Qwen3.5-Flash Alibaba (Qwen)

42.5

Rank #112 Confirmed

Summary

  • They share 26 benchmarks with published results for both. DeepSeek V4.1 Flash scores higher in 8 categories and Qwen3.5-Flash in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where DeepSeek V4.1 Flash leads 66.7 to 37.4.
  • The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 67.4% for DeepSeek V4.1 Flash and 18.2% for Qwen3.5-Flash.
  • Qwen3.5-Flash is cheaper at $0.10 / $0.40 per million input/output tokens, against $0.15 / $0.60 for DeepSeek V4.1 Flash.
  • DeepSeek V4.1 Flash has downloadable open weights; the other is API-only.

Side by side

DeepSeek V4.1 FlashQwen3.5-Flash
ProviderDeepSeekAlibaba (Qwen)
Noometry Index52.842.5
Released2026-09-092026-02-23
WeightsOpenProprietary
Context window1M1M
Max output393K66K
Input $ / M tokens$0.15$0.10
Output $ / M tokens$0.60$0.40
Results tracked3732

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Category by category

Coding DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 52.9 (#32), Qwen3.5-Flash: 34.2 (#242)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
LMArena WebDev16191244
LMArena Coding15061412
ALE-Bench1,092221.8
SciCode51.9%—

Agentic & Tool Use Not comparable

DeepSeek V4.1 Flash: 31.2 (#69), Qwen3.5-Flash: —

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
APEX-Agents39.5%—
GDP.pdf19.8%—
Vending-Bench 2—462.69

Reasoning DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 50.2 (#36), Qwen3.5-Flash: 33.7 (#72)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
LMArena Hard Prompts14831403
Mystery Game Puzzles43%20%
DTBench89.9%82.9%
LMCA47%29.1%
Epoch Capabilities Index154.9143.98
NYT Connections (extended)89.6%—
CritPt14.3%—
Chess Puzzles—21%
Surface Evolver Bench46.3%—

Math DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 66.7 (#25), Qwen3.5-Flash: 37.4 (#158)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
FrontierMath (Tiers 1-3)67.4%18.2%
OTIS Mock AIME 2024-202598.3%84.4%
LMArena Math14771407
FrontierMath Tier 426.8%—
ProofBench54%—
FrontierMath (Feb 2025 set)—6.2%
FrontierMath Tier 4 (v1)—0%

Knowledge DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 57.9 (#38), Qwen3.5-Flash: 43.2 (#93)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
GPQA Diamond89.8%82.3%
LMArena Expert15061407
SimpleQA Verified—20.3%
Vectara Hallucination Rate—10.5%

Multimodal Not comparable

DeepSeek V4.1 Flash: 39.1 (#61), Qwen3.5-Flash: —

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
LMArena Vision1277—
Furniture Assembly34.2%—

Multilingual DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 55.0 (#35), Qwen3.5-Flash: 50.5 (#121)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
LMArena Non-English14481385
LMArena Chinese14971446
LMArena French14521412
LMArena German14841390
LMArena Japanese14121368
LMArena Korean14521344
LMArena Russian14711379
LMArena Spanish14591400

Instruction Following DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 77.3 (#26), Qwen3.5-Flash: 72.6 (#139)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
LMArena Instruction Following14741374

Long Context DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 45.2 (#47), Qwen3.5-Flash: 42.4 (#124)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
LMArena Longer Query14751392

Writing & Preference DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 65.4 (#48), Qwen3.5-Flash: 57.9 (#122)

BenchmarkDeepSeek V4.1 FlashQwen3.5-Flash
LMArena Text14621397
LMArena Creative Writing14351343
LMArena Multi-Turn14571393
EQ-Bench Creative Writing1540—

Frequently asked questions

Is DeepSeek V4.1 Flash better than Qwen3.5-Flash?

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 42.5 on the Noometry Index.

Which is cheaper, DeepSeek V4.1 Flash or Qwen3.5-Flash?

Qwen3.5-Flash is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; DeepSeek V4.1 Flash lists at $0.15 and $0.60.

Is DeepSeek V4.1 Flash or Qwen3.5-Flash better for coding?

DeepSeek V4.1 Flash scores higher on coding benchmarks: 52.9 versus 34.2 in the Noometry coding category.

Which has the bigger context window?

Both accept 1M tokens.

How many benchmarks do DeepSeek V4.1 Flash and Qwen3.5-Flash share?

26 benchmarks have published results for both models. DeepSeek V4.1 Flash has 37 scored results on Noometry and Qwen3.5-Flash has 32.

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