Model comparison

DeepSeek V4.1 Flash vs Qwen3.5-Flash

DeepSeek V4.1 Flash is the stronger model overall, scoring 50.3 to 42.3 on the Noometry Index.

Last verified October 10, 2026. 19 shared benchmarks.

DeepSeek V4.1 Flash

DeepSeek

50.3

Rank #40 Confirmed

Qwen3.5-Flash

Alibaba (Qwen)

42.3

Rank #105 Confirmed

Summary

They share 19 benchmarks with published results for both. DeepSeek V4.1 Flash scores higher in 7 categories and Qwen3.5-Flash in 1 category; 8 gaps are clear of the uncertainty.
The widest gap is in coding, where DeepSeek V4.1 Flash leads 52.8 to 33.9.
The biggest single-benchmark swing is LMCA: 47% for DeepSeek V4.1 Flash and 29.1% 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 Flash and Qwen3.5-Flash specifications
	DeepSeek V4.1 Flash	Qwen3.5-Flash
Provider	DeepSeek	Alibaba (Qwen)
Noometry Index	50.3	42.3
Released	2026-09-09	2026-02-23
Weights	Open	Proprietary
Context window	1M	1M
Max output	393K	66K
Input $ / M tokens	$0.15	$0.10
Output $ / M tokens	$0.60	$0.40
Results tracked	25	32

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Category by category

Coding DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 52.8 (#29), Qwen3.5-Flash: 33.9 (#234)

Coding benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena WebDev	1620	1243
LMArena Coding	1511	1412
ALE-Bench	1,092	221.8
SciCode	51.9%	—

Agentic & Tool Use Not comparable

DeepSeek V4.1 Flash: —, Qwen3.5-Flash: —

Agentic & Tool Use benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
Vending-Bench 2	—	462.69

Reasoning DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 46.2 (#39), Qwen3.5-Flash: 32.9 (#63)

Reasoning benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena Hard Prompts	1485	1404
DTBench	89.9%	82.9%
LMCA	47%	29.1%
Epoch Capabilities Index	155.01	143.98
NYT Connections (extended)	89.6%	—
CritPt	14.3%	—
Chess Puzzles	—	21%
Mystery Game Puzzles	—	20%
Surface Evolver Bench	46.3%	—

Math DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 48.4 (#52), Qwen3.5-Flash: 36.3 (#117)

Math benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena Math	1493	1407
FrontierMath (Tiers 1-3)	—	18.2%
OTIS Mock AIME 2024-2025	—	84.4%
ProofBench	54%	—
FrontierMath (Feb 2025 set)	—	6.2%
FrontierMath Tier 4 (v1)	—	0%

Knowledge Qwen3.5-Flash leads

DeepSeek V4.1 Flash: 41.6 (#97), Qwen3.5-Flash: 43.2 (#84)

Knowledge benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena Expert	1505	1408
GPQA Diamond	—	82.3%
SimpleQA Verified	—	20.3%
Vectara Hallucination Rate	—	10.5%

Multilingual DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 55.5 (#29), Qwen3.5-Flash: 50.7 (#116)

Multilingual benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena Non-English	1452	1385
LMArena Chinese	1506	1446
LMArena French	1448	1412
LMArena Russian	1473	1379
LMArena Spanish	1499	1399
LMArena German	—	1389
LMArena Japanese	—	1369
LMArena Korean	—	1344

Instruction Following DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 77.6 (#24), Qwen3.5-Flash: 72.8 (#133)

Instruction Following benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena Instruction Following	1475	1374

Long Context DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 45.2 (#46), Qwen3.5-Flash: 42.4 (#119)

Long Context benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena Longer Query	1476	1392

Writing & Preference DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 65.8 (#43), Qwen3.5-Flash: 58.2 (#117)

Writing & Preference benchmarks
Benchmark	DeepSeek V4.1 Flash	Qwen3.5-Flash
LMArena Text	1465	1397
LMArena Creative Writing	1436	1343
LMArena Multi-Turn	1460	1393
EQ-Bench Creative Writing	1540	—

Frequently asked questions

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

DeepSeek V4.1 Flash is the stronger model overall, scoring 50.3 to 42.3 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: 52.8 versus 33.9 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?

19 benchmarks have published results for both models. DeepSeek V4.1 Flash has 25 scored results on Noometry and Qwen3.5-Flash has 32.