Noometry

Model comparison

DeepSeek V4.1 Flash vs Grok 4.1 Fast

DeepSeek V4.1 Flash is the stronger model overall, scoring 50.3 to 40.9 on the Noometry Index.

Last verified . 20 shared benchmarks.

DeepSeek V4.1 Flash DeepSeek

50.3

Rank #40 Confirmed

Grok 4.1 Fast xAI

40.9

Rank #131 Confirmed

Summary

  • They share 20 benchmarks with published results for both. DeepSeek V4.1 Flash scores higher in 8 categories and Grok 4.1 Fast in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in coding, where DeepSeek V4.1 Flash leads 52.8 to 33.8.
  • The biggest single-benchmark swing is ProofBench: 54% for DeepSeek V4.1 Flash and 4% for Grok 4.1 Fast.
  • Both cost about the same: $0.15 input and $0.60 output per million tokens.
  • DeepSeek V4.1 Flash accepts more context: 1M tokens versus 128K.
  • DeepSeek V4.1 Flash has downloadable open weights; the other is API-only.

Side by side

DeepSeek V4.1 FlashGrok 4.1 Fast
ProviderDeepSeekxAI
Noometry Index50.340.9
Released2026-09-092025-06-27
WeightsOpenProprietary
Context window1M128K
Max output393K30K
Input $ / M tokens$0.15$0.20
Output $ / M tokens$0.60$0.50
Results tracked2532

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Category by category

Coding DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 52.8 (#29), Grok 4.1 Fast: 33.8 (#236)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
LMArena WebDev16201241
LMArena Coding15111411
ALE-Bench1,092394.93
SciCode51.9%—

Agentic & Tool Use Not comparable

DeepSeek V4.1 Flash: —, Grok 4.1 Fast: 36.1 (#35)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
Berkeley Function Calling Leaderboard—69.6%
τ²-bench Banking—13.1%
LMArena Search—1171
Vending-Bench 2—1,107

Reasoning DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 46.2 (#39), Grok 4.1 Fast: 42.3 (#45)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
NYT Connections (extended)89.6%87.4%
LMArena Hard Prompts14851407
DTBench89.9%87.7%
SimpleBench—56%
CritPt14.3%—
LMCA47%—
Surface Evolver Bench46.3%—
Epoch Capabilities Index155.01—
ForecastBench—61

Math DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 48.4 (#52), Grok 4.1 Fast: 30.9 (#201)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
ProofBench54%4%
LMArena Math14931408
MathArena Final-Answer Competitions—60.9%

Knowledge DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 41.6 (#97), Grok 4.1 Fast: 32.6 (#203)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
LMArena Expert15051398
Vectara Hallucination Rate—17.8%

Multimodal Not comparable

DeepSeek V4.1 Flash: —, Grok 4.1 Fast: 36.3 (#71)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
LMArena Vision—1201

Multilingual DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 55.5 (#29), Grok 4.1 Fast: 51.1 (#110)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
LMArena Non-English14521391
LMArena Chinese15061441
LMArena French14481416
LMArena Russian14731387
LMArena Spanish14991411
LMArena German—1404
LMArena Japanese—1347
LMArena Korean—1361

Instruction Following DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 77.6 (#24), Grok 4.1 Fast: 72.8 (#127)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
LMArena Instruction Following14751376

Long Context DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 45.2 (#46), Grok 4.1 Fast: 42.4 (#121)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
LMArena Longer Query14761390

Writing & Preference DeepSeek V4.1 Flash leads

DeepSeek V4.1 Flash: 65.8 (#43), Grok 4.1 Fast: 57.4 (#126)

BenchmarkDeepSeek V4.1 FlashGrok 4.1 Fast
LMArena Text14651408
LMArena Creative Writing14361394
EQ-Bench Creative Writing15401327
LMArena Multi-Turn14601389

Frequently asked questions

Is DeepSeek V4.1 Flash better than Grok 4.1 Fast?

DeepSeek V4.1 Flash is the stronger model overall, scoring 50.3 to 40.9 on the Noometry Index.

Which is cheaper, DeepSeek V4.1 Flash or Grok 4.1 Fast?

DeepSeek V4.1 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Grok 4.1 Fast lists at $0.20 and $0.50.

Is DeepSeek V4.1 Flash or Grok 4.1 Fast better for coding?

DeepSeek V4.1 Flash scores higher on coding benchmarks: 52.8 versus 33.8 in the Noometry coding category.

Which has the bigger context window?

DeepSeek V4.1 Flash does, with 1M tokens against 128K.

How many benchmarks do DeepSeek V4.1 Flash and Grok 4.1 Fast share?

20 benchmarks have published results for both models. DeepSeek V4.1 Flash has 25 scored results on Noometry and Grok 4.1 Fast has 32.

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