Noometry

Model comparison

Claude Sonnet 4.6 vs Grok 4 Fast

Claude Sonnet 4.6 is the stronger model overall, scoring 50.1 to 39.0 on the Noometry Index.

Last verified . 26 shared benchmarks.

Claude Sonnet 4.6 Anthropic

50.1

Rank #42 Confirmed

Grok 4 Fast xAI

39.0

Rank #164 Confirmed

Summary

  • They share 26 benchmarks with published results for both. Claude Sonnet 4.6 scores higher in 8 categories and Grok 4 Fast in 1 category; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Sonnet 4.6 leads 46.1 to 22.5.
  • The biggest single-benchmark swing is ARC-AGI-2: 60.4% for Claude Sonnet 4.6 and 5.3% for Grok 4 Fast.

Side by side

Claude Sonnet 4.6Grok 4 Fast
ProviderAnthropicxAI
Noometry Index50.139.0
Released2026-02-172025-09-19
WeightsProprietaryProprietary
Context window1M—
Max output128K—
Input $ / M tokens$3—
Output $ / M tokens$15—
Results tracked5730

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Category by category

Coding Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 46.0 (#62), Grok 4 Fast: 32.3 (#264)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena WebDev15211160
WeirdML66.1%42.9%
LMArena Coding15041429
SWE-bench Verified75.2%—
DeepSWE29.9%—
FrontierCode24.3%—
SciCode46.8%—
ALE-Bench1,327—

Agentic & Tool Use Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 39.1 (#26), Grok 4 Fast: 29.3 (#80)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena Search12211171
Terminal-Bench53.4%—
APEX-Agents43%—
OSWorld 2.09.3%—
τ²-bench Banking—15.7%
Cybench—30%
DeepResearch Bench54.9%—
OSWorld72.1%—
ExploitBench23.6%—
GBAEval48.8%—
GDP.pdf18%—
Vending-Bench 27,204—

Reasoning Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 46.1 (#40), Grok 4 Fast: 22.5 (#179)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
ARC-AGI-260.4%5.3%
ARC-AGI-186.5%48.5%
LMArena Hard Prompts14851413
DTBench89.9%82.7%
Epoch Capabilities Index152.25144.21
ForecastBench6260.5
Kagi LLM Benchmark—66.1%
NYT Connections (extended)80.9%—
CritPt3.1%—
Chess Puzzles13%—
Thematic Generalization76.3%—
Mystery Game Puzzles16%—
LMCA46.5%—

Math Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 51.9 (#41), Grok 4 Fast: 36.1 (#126)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena Math14631419
OTIS Mock AIME 2024-202585.8%—
ProofBench45%—
FrontierMath (Feb 2025 set)32.4%—
FrontierMath Tier 4 (v1)8.3%—

Knowledge Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 51.6 (#60), Grok 4 Fast: 31.5 (#211)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
Vectara Hallucination Rate10.6%19.7%
LMArena Expert15001411
GPQA Diamond87.4%—
SimpleQA Verified35.5%—

Multimodal Not comparable

Claude Sonnet 4.6: 38.0 (#61), Grok 4 Fast: —

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena Vision1283—
Blueprint-Bench 26.7%—
LMArena Document1482—

Multilingual Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 54.6 (#39), Grok 4 Fast: 51.5 (#106)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena Non-English14401397
LMArena Chinese14911458
LMArena French14651433
LMArena German14281383
LMArena Japanese14191358
LMArena Korean14111359
LMArena Russian14401387
LMArena Spanish14651414

Instruction Following Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 77.6 (#23), Grok 4 Fast: 73.4 (#116)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena Instruction Following14761388

Long Context Grok 4 Fast leads

Claude Sonnet 4.6: 45.3 (#40), Grok 4 Fast: 63.2 (#3)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena Longer Query14791415
Fiction.LiveBench—94.4%

Writing & Preference Claude Sonnet 4.6 leads

Claude Sonnet 4.6: 70.4 (#22), Grok 4 Fast: 60.2 (#96)

BenchmarkClaude Sonnet 4.6Grok 4 Fast
LMArena Text14581407
LMArena Creative Writing14351388
LMArena Multi-Turn14641414
EQ-Bench Creative Writing1810—
EQ-Bench 41207—

Frequently asked questions

Is Claude Sonnet 4.6 better than Grok 4 Fast?

Claude Sonnet 4.6 is the stronger model overall, scoring 50.1 to 39.0 on the Noometry Index.

Is Claude Sonnet 4.6 or Grok 4 Fast better for coding?

Claude Sonnet 4.6 scores higher on coding benchmarks: 46.0 versus 32.3 in the Noometry coding category.

How many benchmarks do Claude Sonnet 4.6 and Grok 4 Fast share?

26 benchmarks have published results for both models. Claude Sonnet 4.6 has 57 scored results on Noometry and Grok 4 Fast has 30.

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