Noometry

Model comparison

Grok 4 Fast vs Inkling

Inkling is the stronger model overall, scoring 44.1 to 39.4 on the Noometry Index.

Last verified . 24 shared benchmarks.

Grok 4 Fast xAI

39.4

Rank #167 Confirmed

Inkling Thinking Machines Lab

44.1

Rank #80 Confirmed

Summary

  • They share 24 benchmarks with published results for both. Grok 4 Fast scores higher in 2 categories and Inkling in 7 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Inkling leads 55.1 to 32.0.
  • The biggest single-benchmark swing is ARC-AGI-2: 5.3% for Grok 4 Fast and 36.5% for Inkling.
  • Inkling has downloadable open weights; the other is API-only.

Side by side

Grok 4 FastInkling
ProviderxAIThinking Machines Lab
Noometry Index39.444.1
Released2025-09-192026-07-15
WeightsProprietaryOpen
Context window—66K
Max output—66K
Input $ / M tokens—$1.87
Output $ / M tokens—$4.68
Results tracked3041

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Category by category

Coding Inkling leads

Grok 4 Fast: 32.5 (#271), Inkling: 34.5 (#234)

BenchmarkGrok 4 FastInkling
LMArena WebDev11591413
WeirdML42.9%32.3%
LMArena Coding14291464
FrontierCode—14%
FrontierSWE—4.1%
SciCode—47%
ALE-Bench—946

Agentic & Tool Use Too close to call

Grok 4 Fast: 29.5 (#86), Inkling: 29.6 (#85)

BenchmarkGrok 4 FastInkling
τ²-bench Banking15.7%25%
APEX-Agents—33.8%
Cybench30%—
LMArena Search1171—

Reasoning Inkling leads

Grok 4 Fast: 22.2 (#201), Inkling: 40.4 (#56)

BenchmarkGrok 4 FastInkling
ARC-AGI-25.3%36.5%
ARC-AGI-148.5%79.5%
LMArena Hard Prompts14121451
DTBench82.7%87.5%
Epoch Capabilities Index144.2148.54
SimpleBench—50%
Kagi LLM Benchmark66.1%—
CritPt—5.4%
Chess Puzzles—21%
LMCA—37.6%
ForecastBench60.5—

Math Grok 4 Fast leads

Grok 4 Fast: 38.9 (#123), Inkling: 31.3 (#225)

BenchmarkGrok 4 FastInkling
LMArena Math14191479
FrontierMath (Tiers 1-3)—33.3%
FrontierMath Tier 4—4.9%
OTIS Mock AIME 2024-2025—88.9%
ProofBench—0%

Knowledge Inkling leads

Grok 4 Fast: 32.0 (#214), Inkling: 55.1 (#49)

BenchmarkGrok 4 FastInkling
LMArena Expert14111465
GPQA Diamond—88.3%
SimpleQA Verified—40.3%
Vectara Hallucination Rate19.7%—

Multilingual Inkling leads

Grok 4 Fast: 51.3 (#111), Inkling: 54.0 (#52)

BenchmarkGrok 4 FastInkling
LMArena Non-English13961434
LMArena Chinese14571490
LMArena French14311458
LMArena German13831446
LMArena Japanese13521429
LMArena Korean13571404
LMArena Russian13891429
LMArena Spanish14151448

Instruction Following Inkling leads

Grok 4 Fast: 73.2 (#121), Inkling: 75.1 (#71)

BenchmarkGrok 4 FastInkling
LMArena Instruction Following13871426

Long Context Grok 4 Fast leads

Grok 4 Fast: 63.2 (#3), Inkling: 43.8 (#86)

BenchmarkGrok 4 FastInkling
LMArena Longer Query14151434
Fiction.LiveBench94.4%—

Writing & Preference Inkling leads

Grok 4 Fast: 60.0 (#102), Inkling: 65.2 (#51)

BenchmarkGrok 4 FastInkling
LMArena Text14071441
LMArena Creative Writing13871387
LMArena Multi-Turn14141436
EQ-Bench Creative Writing—1611
EQ-Bench 4—1226

Frequently asked questions

Is Grok 4 Fast better than Inkling?

Inkling is the stronger model overall, scoring 44.1 to 39.4 on the Noometry Index.

Is Grok 4 Fast or Inkling better for coding?

Inkling scores higher on coding benchmarks: 34.5 versus 32.5 in the Noometry coding category.

How many benchmarks do Grok 4 Fast and Inkling share?

24 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Inkling has 41.

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