Model comparison

Grok 4 Fast vs Qwen3-4B

Grok 4 Fast is the stronger model overall, scoring 39.4 to 31.9 on the Noometry Index.

Last verified . 1 shared benchmarks.

Grok 4 Fast xAI

39.4

Rank #167 Confirmed

Qwen3-4B Alibaba (Qwen)

31.9

Rank #264 Confirmed

Summary

  • They share 1 benchmark with published results for both. Grok 4 Fast scores higher in 3 categories and Qwen3-4B in 1 category; 3 gaps are clear of the uncertainty.
  • The widest gap is in math, where Grok 4 Fast leads 38.9 to 29.7.
  • The biggest single-benchmark swing is Vectara Hallucination Rate: 19.7% for Grok 4 Fast and 5.7% for Qwen3-4B.
  • Qwen3-4B has downloadable open weights; the other is API-only.

Side by side

Grok 4 Fast and Qwen3-4B specifications
Grok 4 FastQwen3-4B
ProviderxAIAlibaba (Qwen)
Noometry Index39.431.9
Released2025-09-192025-04-29
WeightsProprietaryOpen
Context window——
Max output——
Input $ / M tokens——
Output $ / M tokens——
Results tracked306

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Category by category

Coding Not comparable

Grok 4 Fast: 32.5 (#271), Qwen3-4B: —

Coding benchmarks
BenchmarkGrok 4 FastQwen3-4B
LMArena WebDev1159—
WeirdML42.9%—
LMArena Coding1429—

Agentic & Tool Use Grok 4 Fast leads

Grok 4 Fast: 29.5 (#86), Qwen3-4B: 27.6 (#100)

Agentic & Tool Use benchmarks
BenchmarkGrok 4 FastQwen3-4B
Berkeley Function Calling Leaderboard—35.7%
τ²-bench Banking15.7%—
Cybench30%—
LMArena Search1171—

Reasoning Grok 4 Fast leads

Grok 4 Fast: 22.2 (#201), Qwen3-4B: 19.2 (#268)

Reasoning benchmarks
BenchmarkGrok 4 FastQwen3-4B
ARC-AGI-25.3%—
Kagi LLM Benchmark66.1%—
ARC-AGI-148.5%—
Chess Puzzles—4%
LMArena Hard Prompts1412—
DTBench82.7%—
Epoch Capabilities Index144.2—
ForecastBench60.5—

Math Grok 4 Fast leads

Grok 4 Fast: 38.9 (#123), Qwen3-4B: 29.7 (#240)

Math benchmarks
BenchmarkGrok 4 FastQwen3-4B
MathArena Final-Answer Competitions—38.5%
OTIS Mock AIME 2024-2025—52.2%
LMArena Math1419—

Knowledge Too close to call

Grok 4 Fast: 32.0 (#214), Qwen3-4B: 33.0 (#208)

Knowledge benchmarks
BenchmarkGrok 4 FastQwen3-4B
Vectara Hallucination Rate19.7%5.7%
GPQA Diamond—52.3%
LMArena Expert1411—

Multilingual Not comparable

Grok 4 Fast: 51.3 (#111), Qwen3-4B: —

Multilingual benchmarks
BenchmarkGrok 4 FastQwen3-4B
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), Qwen3-4B: —

Instruction Following benchmarks
BenchmarkGrok 4 FastQwen3-4B
LMArena Instruction Following1387—

Long Context Not comparable

Grok 4 Fast: 63.2 (#3), Qwen3-4B: —

Long Context benchmarks
BenchmarkGrok 4 FastQwen3-4B
Fiction.LiveBench94.4%—
LMArena Longer Query1415—

Writing & Preference Not comparable

Grok 4 Fast: 60.0 (#102), Qwen3-4B: —

Writing & Preference benchmarks
BenchmarkGrok 4 FastQwen3-4B
LMArena Text1407—
LMArena Creative Writing1387—
LMArena Multi-Turn1414—

Frequently asked questions

Is Grok 4 Fast better than Qwen3-4B?

Grok 4 Fast is the stronger model overall, scoring 39.4 to 31.9 on the Noometry Index.

How many benchmarks do Grok 4 Fast and Qwen3-4B share?

1 benchmark has published results for both models. Grok 4 Fast has 30 scored results on Noometry and Qwen3-4B has 6.

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