Model comparison

DeepSeek-V3.1 vs DeepSeek V4.1 Flash

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 42.8 on the Noometry Index.

Last verified . 21 shared benchmarks.

DeepSeek-V3.1 DeepSeek

42.8

Rank #108 Confirmed

DeepSeek V4.1 Flash DeepSeek

52.8

Rank #38 Confirmed

Summary

  • They share 21 benchmarks with published results for both. DeepSeek-V3.1 scores higher in 0 categories and DeepSeek V4.1 Flash in 8 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where DeepSeek V4.1 Flash leads 66.7 to 38.9.
  • The biggest single-benchmark swing is LMCA: 24.3% for DeepSeek-V3.1 and 47% for DeepSeek V4.1 Flash.
  • DeepSeek V4.1 Flash is cheaper at $0.15 / $0.60 per million input/output tokens, against $0.25 / $0.95 for DeepSeek-V3.1.
  • DeepSeek V4.1 Flash accepts more context: 1M tokens versus 164K.

Side by side

DeepSeek-V3.1 and DeepSeek V4.1 Flash specifications
DeepSeek-V3.1DeepSeek V4.1 Flash
ProviderDeepSeekDeepSeek
Noometry Index42.852.8
Released2025-08-212026-09-09
WeightsOpenOpen
Context window164K1M
Max output8K393K
Input $ / M tokens$0.25$0.15
Output $ / M tokens$0.95$0.60
Results tracked2737

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Category by category

Coding DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 40.3 (#144), DeepSeek V4.1 Flash: 52.9 (#32)

Coding benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Coding14171506
LMArena WebDev—1619
SciCode—51.9%
WeirdML38.4%—
ALE-Bench—1,092

Agentic & Tool Use Not comparable

DeepSeek-V3.1: —, DeepSeek V4.1 Flash: 31.2 (#69)

Agentic & Tool Use benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
APEX-Agents—39.5%
GDP.pdf—19.8%

Reasoning DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 27.9 (#110), DeepSeek V4.1 Flash: 50.2 (#36)

Reasoning benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Hard Prompts14171483
DTBench82.7%89.9%
LMCA24.3%47%
Epoch Capabilities Index139.92154.9
SimpleBench40%—
Kagi LLM Benchmark53.2%—
NYT Connections (extended)—89.6%
CritPt—14.3%
Mystery Game Puzzles—43%
Surface Evolver Bench—46.3%
ForecastBench58—

Math DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 38.9 (#122), DeepSeek V4.1 Flash: 66.7 (#25)

Math benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Math14201477
FrontierMath (Tiers 1-3)—67.4%
FrontierMath Tier 4—26.8%
OTIS Mock AIME 2024-2025—98.3%
ProofBench—54%

Knowledge DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 43.7 (#90), DeepSeek V4.1 Flash: 57.9 (#38)

Knowledge benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Expert14051506
GPQA Diamond—89.8%
Vectara Hallucination Rate5.5%—

Multimodal Not comparable

DeepSeek-V3.1: —, DeepSeek V4.1 Flash: 39.1 (#61)

Multimodal benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Vision—1277
Furniture Assembly—34.2%

Multilingual DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 51.6 (#106), DeepSeek V4.1 Flash: 55.0 (#35)

Multilingual benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Non-English14001448
LMArena Chinese14691497
LMArena French14471452
LMArena German14111484
LMArena Japanese13781412
LMArena Korean13371452
LMArena Russian14051471
LMArena Spanish14311459

Instruction Following DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 73.9 (#110), DeepSeek V4.1 Flash: 77.3 (#26)

Instruction Following benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Instruction Following14001474

Long Context DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 36.3 (#232), DeepSeek V4.1 Flash: 45.2 (#47)

Long Context benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Longer Query14221475
Fiction.LiveBench52.8%—

Writing & Preference DeepSeek V4.1 Flash leads

DeepSeek-V3.1: 60.3 (#98), DeepSeek V4.1 Flash: 65.4 (#48)

Writing & Preference benchmarks
BenchmarkDeepSeek-V3.1DeepSeek V4.1 Flash
LMArena Text14201462
LMArena Creative Writing14011435
EQ-Bench Creative Writing14361540
LMArena Multi-Turn14081457

Frequently asked questions

Is DeepSeek-V3.1 better than DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is the stronger model overall, scoring 52.8 to 42.8 on the Noometry Index.

Which is cheaper, DeepSeek-V3.1 or DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; DeepSeek-V3.1 lists at $0.25 and $0.95.

Is DeepSeek-V3.1 or DeepSeek V4.1 Flash better for coding?

DeepSeek V4.1 Flash scores higher on coding benchmarks: 52.9 versus 40.3 in the Noometry coding category.

Which has the bigger context window?

DeepSeek V4.1 Flash does, with 1M tokens against 164K.

How many benchmarks do DeepSeek-V3.1 and DeepSeek V4.1 Flash share?

21 benchmarks have published results for both models. DeepSeek-V3.1 has 27 scored results on Noometry and DeepSeek V4.1 Flash has 37.

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