Model comparison

Grok 4 Fast vs Qwen3 8B

Grok 4 Fast is the stronger model overall, scoring 39.4 to 33.7 on the Noometry Index.

Last verified . 4 shared benchmarks.

Grok 4 Fast xAI

39.4

Rank #167 Confirmed

Qwen3 8B Alibaba (Qwen)

33.7

Rank #238 Confirmed

Summary

  • They share 4 benchmarks with published results for both. Grok 4 Fast scores higher in 3 categories and Qwen3 8B in 3 categories; 5 gaps are clear of the uncertainty.
  • The widest gap is in long context, where Grok 4 Fast leads 63.2 to 37.9.
  • The biggest single-benchmark swing is Fiction.LiveBench: 94.4% for Grok 4 Fast and 62.1% for Qwen3 8B.
  • Qwen3 8B has downloadable open weights; the other is API-only.

Side by side

Grok 4 Fast and Qwen3 8B specifications
Grok 4 FastQwen3 8B
ProviderxAIAlibaba (Qwen)
Noometry Index39.433.7
Released2025-09-192025-04
WeightsProprietaryOpen
Context window—131K
Max output—8K
Input $ / M tokens—$0.18
Output $ / M tokens—$0.70
Results tracked3011

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Category by category

Coding Qwen3 8B leads

Grok 4 Fast: 32.5 (#271), Qwen3 8B: 34.0 (#248)

Coding benchmarks
BenchmarkGrok 4 FastQwen3 8B
LMArena WebDev1159—
SciCode—22.6%
WeirdML42.9%—
LMArena Coding1429—

Agentic & Tool Use Too close to call

Grok 4 Fast: 29.5 (#86), Qwen3 8B: 30.2 (#78)

Agentic & Tool Use benchmarks
BenchmarkGrok 4 FastQwen3 8B
Berkeley Function Calling Leaderboard—42.6%
τ²-bench Banking15.7%—
Cybench30%—
LMArena Search1171—

Reasoning Grok 4 Fast leads

Grok 4 Fast: 22.2 (#201), Qwen3 8B: 16.6 (#303)

Reasoning benchmarks
BenchmarkGrok 4 FastQwen3 8B
DTBench82.7%59.7%
Epoch Capabilities Index144.2136.17
ARC-AGI-25.3%—
Kagi LLM Benchmark66.1%—
ARC-AGI-148.5%—
CritPt—0%
Chess Puzzles—5%
LMArena Hard Prompts1412—
LMCA—8.8%
ForecastBench60.5—

Math Grok 4 Fast leads

Grok 4 Fast: 38.9 (#123), Qwen3 8B: 34.9 (#191)

Math benchmarks
BenchmarkGrok 4 FastQwen3 8B
OTIS Mock AIME 2024-2025—56.1%
LMArena Math1419—

Knowledge Qwen3 8B leads

Grok 4 Fast: 32.0 (#214), Qwen3 8B: 36.1 (#173)

Knowledge benchmarks
BenchmarkGrok 4 FastQwen3 8B
Vectara Hallucination Rate19.7%4.8%
GPQA Diamond—56.8%
LMArena Expert1411—

Multilingual Not comparable

Grok 4 Fast: 51.3 (#111), Qwen3 8B: —

Multilingual benchmarks
BenchmarkGrok 4 FastQwen3 8B
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 8B: —

Instruction Following benchmarks
BenchmarkGrok 4 FastQwen3 8B
LMArena Instruction Following1387—

Long Context Grok 4 Fast leads

Grok 4 Fast: 63.2 (#3), Qwen3 8B: 37.9 (#210)

Long Context benchmarks
BenchmarkGrok 4 FastQwen3 8B
Fiction.LiveBench94.4%62.1%
LMArena Longer Query1415—

Writing & Preference Not comparable

Grok 4 Fast: 60.0 (#102), Qwen3 8B: —

Writing & Preference benchmarks
BenchmarkGrok 4 FastQwen3 8B
LMArena Text1407—
LMArena Creative Writing1387—
LMArena Multi-Turn1414—

Frequently asked questions

Is Grok 4 Fast better than Qwen3 8B?

Grok 4 Fast is the stronger model overall, scoring 39.4 to 33.7 on the Noometry Index.

Is Grok 4 Fast or Qwen3 8B better for coding?

Qwen3 8B scores higher on coding benchmarks: 34.0 versus 32.5 in the Noometry coding category.

How many benchmarks do Grok 4 Fast and Qwen3 8B share?

4 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Qwen3 8B has 11.

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