Model comparison

Grok 4 Fast vs Phi-3.5-mini

Grok 4 Fast has enough public results to be ranked (#167); Phi-3.5-mini does not yet, so treat this comparison as directional.

Last verified . 0 shared benchmarks.

Grok 4 Fast xAI

39.4

Rank #167 Confirmed

Phi-3.5-mini Microsoft

36.9

Unranked Sparse

Summary

  • Phi-3.5-mini has downloadable open weights; the other is API-only.

Side by side

Grok 4 Fast and Phi-3.5-mini specifications
Grok 4 FastPhi-3.5-mini
ProviderxAIMicrosoft
Noometry Index39.436.9
Released2025-09-192024-08-16
WeightsProprietaryOpen
Context window——
Max output——
Input $ / M tokens——
Output $ / M tokens——
Results tracked305

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Category by category

Coding Phi-3.5-mini leads

Grok 4 Fast: 32.5 (#271), Phi-3.5-mini: 34.6 (#232)

Coding benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
LMArena WebDev1159—
WeirdML42.9%—
BigCodeBench Instruct—32.8%
LMArena Coding1429—
BigCodeBench Complete—38.5%

Agentic & Tool Use Not comparable

Grok 4 Fast: 29.5 (#86), Phi-3.5-mini: —

Agentic & Tool Use benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
τ²-bench Banking15.7%—
Cybench30%—
LMArena Search1171—

Reasoning Not comparable

Grok 4 Fast: 22.2 (#201), Phi-3.5-mini: —

Reasoning benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
ARC-AGI-25.3%—
Kagi LLM Benchmark66.1%—
ARC-AGI-148.5%—
LMArena Hard Prompts1412—
DTBench82.7%—
Epoch Capabilities Index144.2—
ForecastBench60.5—
PIQA—81%

Math Not comparable

Grok 4 Fast: 38.9 (#123), Phi-3.5-mini: —

Math benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
LMArena Math1419—
GSM8K—86.2%

Knowledge Not comparable

Grok 4 Fast: 32.0 (#214), Phi-3.5-mini: —

Knowledge benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
Vectara Hallucination Rate19.7%—
LMArena Expert1411—
BoolQ—78%

Multilingual Not comparable

Grok 4 Fast: 51.3 (#111), Phi-3.5-mini: —

Multilingual benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
LMArena Non-English1396—
LMArena Chinese1457—
LMArena French1431—
LMArena German1383—
LMArena Japanese1352—
LMArena Korean1357—
LMArena Russian1389—
LMArena Spanish1415—

Instruction Following Not comparable

Grok 4 Fast: 73.2 (#121), Phi-3.5-mini: —

Instruction Following benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
LMArena Instruction Following1387—

Long Context Not comparable

Grok 4 Fast: 63.2 (#3), Phi-3.5-mini: —

Long Context benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
Fiction.LiveBench94.4%—
LMArena Longer Query1415—

Writing & Preference Not comparable

Grok 4 Fast: 60.0 (#102), Phi-3.5-mini: —

Writing & Preference benchmarks
BenchmarkGrok 4 FastPhi-3.5-mini
LMArena Text1407—
LMArena Creative Writing1387—
LMArena Multi-Turn1414—

Frequently asked questions

Is Grok 4 Fast better than Phi-3.5-mini?

Grok 4 Fast has enough public results to be ranked (#167); Phi-3.5-mini does not yet, so treat this comparison as directional.

Is Grok 4 Fast or Phi-3.5-mini better for coding?

Phi-3.5-mini scores higher on coding benchmarks: 34.6 versus 32.5 in the Noometry coding category.

How many benchmarks do Grok 4 Fast and Phi-3.5-mini share?

0 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Phi-3.5-mini has 5.

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