Model comparison

Grok-2 (Dec 2024) vs Grok 4.1 Fast

Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 33.4 on the Noometry Index.

Last verified . 19 shared benchmarks.

Grok-2 (Dec 2024) xAI

33.4

Rank #233 Confirmed

Grok 4.1 Fast xAI

40.9

Rank #131 Confirmed

Summary

  • They share 19 benchmarks with published results for both. Grok-2 (Dec 2024) scores higher in 0 categories and Grok 4.1 Fast in 8 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.1 Fast leads 42.3 to 16.4.
  • The biggest single-benchmark swing is SimpleBench: 22.7% for Grok-2 (Dec 2024) and 56% for Grok 4.1 Fast.

Side by side

Grok-2 (Dec 2024) and Grok 4.1 Fast specifications
Grok-2 (Dec 2024)Grok 4.1 Fast
ProviderxAIxAI
Noometry Index33.440.9
Released2024-08-132025-06-27
WeightsProprietaryProprietary
Context window—128K
Max output—30K
Input $ / M tokens—$0.20
Output $ / M tokens—$0.50
Results tracked3432

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Category by category

Coding Too close to call

Grok-2 (Dec 2024): 32.9 (#254), Grok 4.1 Fast: 33.8 (#236)

Coding benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Coding12881411
LMArena WebDev—1241
WeirdML22.2%—
LiveBench Coding46.4%—
ALE-Bench—394.93

Agentic & Tool Use Not comparable

Grok-2 (Dec 2024): —, Grok 4.1 Fast: 36.1 (#35)

Agentic & Tool Use benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
Berkeley Function Calling Leaderboard—69.6%
τ²-bench Banking—13.1%
LMArena Search—1171
Vending-Bench 2—1,107

Reasoning Grok 4.1 Fast leads

Grok-2 (Dec 2024): 16.4 (#294), Grok 4.1 Fast: 42.3 (#45)

Reasoning benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
SimpleBench22.7%56%
LMArena Hard Prompts12721407
DTBench65.2%87.7%
NYT Connections (extended)—87.4%
LiveBench Reasoning54.8%—
LiveBench Data Analysis54.5%—
Epoch Capabilities Index130.48—
ForecastBench—61
LiveBench54.3%—

Math Grok 4.1 Fast leads

Grok-2 (Dec 2024): 19.6 (#278), Grok 4.1 Fast: 30.9 (#201)

Math benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Math12831408
MathArena Final-Answer Competitions—60.9%
OTIS Mock AIME 2024-202511.5%—
ProofBench—4%
LiveBench Math54.9%—
MATH Level 563.5%—
FrontierMath (Feb 2025 set)0.7%—

Knowledge Grok 4.1 Fast leads

Grok-2 (Dec 2024): 29.8 (#225), Grok 4.1 Fast: 32.6 (#203)

Knowledge benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Expert12541398
GPQA Diamond53.8%—
Confabulations20.1%—
Vectara Hallucination Rate—17.8%

Multimodal Not comparable

Grok-2 (Dec 2024): —, Grok 4.1 Fast: 36.3 (#71)

Multimodal benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Vision—1201

Multilingual Grok 4.1 Fast leads

Grok-2 (Dec 2024): 43.3 (#183), Grok 4.1 Fast: 51.1 (#110)

Multilingual benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Non-English12821391
LMArena Chinese12891441
LMArena French13171416
LMArena German12871404
LMArena Japanese12441347
LMArena Korean12371361
LMArena Russian12861387
LMArena Spanish12811411

Instruction Following Grok 4.1 Fast leads

Grok-2 (Dec 2024): 67.1 (#197), Grok 4.1 Fast: 72.8 (#127)

Instruction Following benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Instruction Following12701376
LiveBench Instruction Following69.6%—

Long Context Grok 4.1 Fast leads

Grok-2 (Dec 2024): 38.7 (#186), Grok 4.1 Fast: 42.4 (#121)

Long Context benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Longer Query12761390

Writing & Preference Grok 4.1 Fast leads

Grok-2 (Dec 2024): 48.8 (#192), Grok 4.1 Fast: 57.4 (#126)

Writing & Preference benchmarks
BenchmarkGrok-2 (Dec 2024)Grok 4.1 Fast
LMArena Text13051408
LMArena Creative Writing12841394
LMArena Multi-Turn12901389
Short-Story Creative Writing63.6%—
EQ-Bench Creative Writing—1327
LiveBench Language45.6%—

Frequently asked questions

Is Grok-2 (Dec 2024) better than Grok 4.1 Fast?

Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 33.4 on the Noometry Index.

Is Grok-2 (Dec 2024) or Grok 4.1 Fast better for coding?

They score almost the same on coding (32.9 vs 33.8); test both on your own repository before choosing.

How many benchmarks do Grok-2 (Dec 2024) and Grok 4.1 Fast share?

19 benchmarks have published results for both models. Grok-2 (Dec 2024) has 34 scored results on Noometry and Grok 4.1 Fast has 32.

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