Model comparison

Grok 4.1 Fast vs Phi 3 Small 8k Instruct

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 29.3 on the Noometry Index.

Last verified . 17 shared benchmarks.

Grok 4.1 Fast xAI

41.4

Rank #136 Confirmed

Phi 3 Small 8k Instruct Microsoft

29.3

Rank #314 Confirmed

Summary

  • They share 17 benchmarks with published results for both. Grok 4.1 Fast scores higher in 8 categories and Phi 3 Small 8k Instruct in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 14.8.
  • Phi 3 Small 8k Instruct has downloadable open weights; the other is API-only.

Side by side

Grok 4.1 Fast and Phi 3 Small 8k Instruct specifications
Grok 4.1 FastPhi 3 Small 8k Instruct
ProviderxAIMicrosoft
Noometry Index41.429.3
Released2025-06-272024-04-23
WeightsProprietaryOpen
Context window128K—
Max output30K—
Input $ / M tokens$0.20—
Output $ / M tokens$0.50—
Results tracked3232

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Category by category

Coding Grok 4.1 Fast leads

Grok 4.1 Fast: 34.1 (#245), Phi 3 Small 8k Instruct: 27.9 (#318)

Coding benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Coding14111101
LMArena WebDev1242—
LiveBench Coding—20.3%
ALE-Bench394.93—

Agentic & Tool Use Not comparable

Grok 4.1 Fast: 36.3 (#39), Phi 3 Small 8k Instruct: —

Agentic & Tool Use benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
Berkeley Function Calling Leaderboard69.6%—
τ²-bench Banking13.1%—
LMArena Search1171—
Vending-Bench 21,107—

Reasoning Grok 4.1 Fast leads

Grok 4.1 Fast: 43.4 (#49), Phi 3 Small 8k Instruct: 14.8 (#323)

Reasoning benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Hard Prompts14071100
SimpleBench56%—
NYT Connections (extended)87.4%—
LiveBench Reasoning—15.9%
DTBench87.7%—
LiveBench Data Analysis—30.3%
Adversarial NLI—58.1%
BIG-Bench Hard—79.1%
ForecastBench61—
HellaSwag—77%
LiveBench—24%
WinoGrande—81.5%

Math Grok 4.1 Fast leads

Grok 4.1 Fast: 31.9 (#221), Phi 3 Small 8k Instruct: 27.6 (#248)

Math benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Math14081151
MathArena Final-Answer Competitions60.9%—
ProofBench4%—
LiveBench Math—17.6%

Knowledge Grok 4.1 Fast leads

Grok 4.1 Fast: 33.1 (#207), Phi 3 Small 8k Instruct: 29.1 (#240)

Knowledge benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Expert13991067
Vectara Hallucination Rate17.8%—
ARC (AI2) Challenge—90.7%
MMLU—75.7%
OpenBookQA—88%
TriviaQA—58.1%

Multimodal Not comparable

Grok 4.1 Fast: 37.0 (#76), Phi 3 Small 8k Instruct: —

Multimodal benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Vision1201—

Multilingual Grok 4.1 Fast leads

Grok 4.1 Fast: 51.0 (#114), Phi 3 Small 8k Instruct: 28.5 (#272)

Multilingual benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Non-English13911058
LMArena Chinese14411061
LMArena French14151135
LMArena German14041080
LMArena Japanese1349966
LMArena Korean1361894
LMArena Russian13871111
LMArena Spanish14131111

Instruction Following Grok 4.1 Fast leads

Grok 4.1 Fast: 72.7 (#133), Phi 3 Small 8k Instruct: 51.9 (#292)

Instruction Following benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Instruction Following13761087
LiveBench Instruction Following—47.2%

Long Context Grok 4.1 Fast leads

Grok 4.1 Fast: 42.4 (#126), Phi 3 Small 8k Instruct: 33.0 (#267)

Long Context benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Longer Query13901088

Writing & Preference Grok 4.1 Fast leads

Grok 4.1 Fast: 57.2 (#131), Phi 3 Small 8k Instruct: 31.1 (#284)

Writing & Preference benchmarks
BenchmarkGrok 4.1 FastPhi 3 Small 8k Instruct
LMArena Text14081110
LMArena Creative Writing13941083
LMArena Multi-Turn13891068
EQ-Bench Creative Writing1327—
LiveBench Language—12.9%

Frequently asked questions

Is Grok 4.1 Fast better than Phi 3 Small 8k Instruct?

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 29.3 on the Noometry Index.

Is Grok 4.1 Fast or Phi 3 Small 8k Instruct better for coding?

Grok 4.1 Fast scores higher on coding benchmarks: 34.1 versus 27.9 in the Noometry coding category.

How many benchmarks do Grok 4.1 Fast and Phi 3 Small 8k Instruct share?

17 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Phi 3 Small 8k Instruct has 32.

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