Noometry

Model comparison

Grok 4 Fast vs Mistral Medium 3.5

Grok 4 Fast and Mistral Medium 3.5 score almost the same on the Noometry Index (39.4 vs 40.2), so choose on price, context window or the category you care about most.

Last verified . 19 shared benchmarks.

Grok 4 Fast xAI

39.4

Rank #167 Confirmed

Mistral Medium 3.5 Mistral AI

40.2

Rank #152 Confirmed

Summary

  • They share 19 benchmarks with published results for both. Grok 4 Fast scores higher in 3 categories and Mistral Medium 3.5 in 5 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in long context, where Grok 4 Fast leads 63.2 to 43.2.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 66.1% for Grok 4 Fast and 41.4% for Mistral Medium 3.5.
  • Mistral Medium 3.5 has downloadable open weights; the other is API-only.

Side by side

Grok 4 FastMistral Medium 3.5
ProviderxAIMistral AI
Noometry Index39.440.2
Released2025-09-19—
WeightsProprietaryOpen
Context window—262K
Max output—210K
Input $ / M tokens—$1.50
Output $ / M tokens—$7.50
Results tracked3022

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Category by category

Coding Mistral Medium 3.5 leads

Grok 4 Fast: 32.5 (#271), Mistral Medium 3.5: 36.0 (#213)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena WebDev11591264
LMArena Coding14291461
WeirdML42.9%—

Agentic & Tool Use Not comparable

Grok 4 Fast: 29.5 (#86), Mistral Medium 3.5: —

BenchmarkGrok 4 FastMistral Medium 3.5
τ²-bench Banking15.7%—
Cybench30%—
LMArena Search1171—

Reasoning Grok 4 Fast leads

Grok 4 Fast: 22.2 (#201), Mistral Medium 3.5: 17.3 (#295)

BenchmarkGrok 4 FastMistral Medium 3.5
Kagi LLM Benchmark66.1%41.4%
LMArena Hard Prompts14121436
Epoch Capabilities Index144.2141.35
ARC-AGI-25.3%—
NYT Connections (extended)—12.9%
ARC-AGI-148.5%—
DTBench82.7%—
ForecastBench60.5—

Math Too close to call

Grok 4 Fast: 38.9 (#123), Mistral Medium 3.5: 39.1 (#113)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena Math14191431

Knowledge Mistral Medium 3.5 leads

Grok 4 Fast: 32.0 (#214), Mistral Medium 3.5: 40.0 (#126)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena Expert14111432
Vectara Hallucination Rate19.7%—

Multimodal Not comparable

Grok 4 Fast: —, Mistral Medium 3.5: 38.3 (#65)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena Vision—1223

Multilingual Too close to call

Grok 4 Fast: 51.3 (#111), Mistral Medium 3.5: 51.9 (#100)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena Non-English13961404
LMArena Chinese14571442
LMArena French14311448
LMArena German13831451
LMArena Korean13571385
LMArena Russian13891395
LMArena Spanish14151409
LMArena Japanese1352—

Instruction Following Mistral Medium 3.5 leads

Grok 4 Fast: 73.2 (#121), Mistral Medium 3.5: 74.6 (#90)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena Instruction Following13871415

Long Context Grok 4 Fast leads

Grok 4 Fast: 63.2 (#3), Mistral Medium 3.5: 43.2 (#103)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena Longer Query14151415
Fiction.LiveBench94.4%—

Writing & Preference Grok 4 Fast leads

Grok 4 Fast: 60.0 (#102), Mistral Medium 3.5: 58.5 (#117)

BenchmarkGrok 4 FastMistral Medium 3.5
LMArena Text14071421
LMArena Creative Writing13871374
LMArena Multi-Turn14141423
EQ-Bench 4—993

Frequently asked questions

Is Grok 4 Fast better than Mistral Medium 3.5?

Grok 4 Fast and Mistral Medium 3.5 score almost the same on the Noometry Index (39.4 vs 40.2), so choose on price, context window or the category you care about most.

Is Grok 4 Fast or Mistral Medium 3.5 better for coding?

Mistral Medium 3.5 scores higher on coding benchmarks: 36.0 versus 32.5 in the Noometry coding category.

How many benchmarks do Grok 4 Fast and Mistral Medium 3.5 share?

19 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Mistral Medium 3.5 has 22.

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