Noometry

Model comparison

Grok 4.1 Fast vs Muse Spark

Muse Spark is the stronger model overall, scoring 50.6 to 41.4 on the Noometry Index.

Last verified . 18 shared benchmarks.

Grok 4.1 Fast xAI

41.4

Rank #136 Confirmed

Muse Spark Meta

50.6

Rank #46 Confirmed

Summary

  • They share 18 benchmarks with published results for both. Grok 4.1 Fast scores higher in 1 category and Muse Spark in 8 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Muse Spark leads 65.7 to 33.1.
  • The biggest single-benchmark swing is ProofBench: 4% for Grok 4.1 Fast and 17% for Muse Spark.

Side by side

Grok 4.1 FastMuse Spark
ProviderxAIMeta
Noometry Index41.450.6
Released2025-06-272026-04-08
WeightsProprietaryProprietary
Context window128K—
Max output30K—
Input $ / M tokens$0.20—
Output $ / M tokens$0.50—
Results tracked3227

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Category by category

Coding Muse Spark leads

Grok 4.1 Fast: 34.1 (#245), Muse Spark: 46.2 (#69)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Coding14111481
LMArena WebDev1242—
SciCode—51.5%
ALE-Bench394.93—

Agentic & Tool Use Not comparable

Grok 4.1 Fast: 36.3 (#39), Muse Spark: —

BenchmarkGrok 4.1 FastMuse Spark
Berkeley Function Calling Leaderboard69.6%—
τ²-bench Banking13.1%—
LMArena Search1171—
Vending-Bench 21,107—

Reasoning Grok 4.1 Fast leads

Grok 4.1 Fast: 43.4 (#49), Muse Spark: 35.9 (#67)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Hard Prompts14071474
SimpleBench56%—
NYT Connections (extended)87.4%—
CritPt—11.3%
DTBench87.7%—
Epoch Capabilities Index—152.04
ForecastBench61—

Math Muse Spark leads

Grok 4.1 Fast: 31.9 (#221), Muse Spark: 47.8 (#66)

BenchmarkGrok 4.1 FastMuse Spark
ProofBench4%17%
LMArena Math14081455
MathArena Final-Answer Competitions60.9%—
OTIS Mock AIME 2024-2025—88.9%
FrontierMath (Feb 2025 set)—39%
FrontierMath Tier 4 (v1)—14.6%

Knowledge Muse Spark leads

Grok 4.1 Fast: 33.1 (#207), Muse Spark: 65.7 (#13)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Expert13991457
GPQA Diamond—89.8%
Humanity's Last Exam—40.6%
Vectara Hallucination Rate17.8%—

Multimodal Muse Spark leads

Grok 4.1 Fast: 37.0 (#76), Muse Spark: 43.4 (#24)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Vision12011306
LMArena Document—1444

Multilingual Muse Spark leads

Grok 4.1 Fast: 51.0 (#114), Muse Spark: 56.1 (#24)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Non-English13911464
LMArena Chinese14411509
LMArena French14151497
LMArena German14041497
LMArena Korean13611459
LMArena Russian13871466
LMArena Spanish14131472
LMArena Japanese1349—

Instruction Following Muse Spark leads

Grok 4.1 Fast: 72.7 (#133), Muse Spark: 75.9 (#51)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Instruction Following13761442

Long Context Muse Spark leads

Grok 4.1 Fast: 42.4 (#126), Muse Spark: 44.4 (#69)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Longer Query13901451

Writing & Preference Muse Spark leads

Grok 4.1 Fast: 57.2 (#131), Muse Spark: 66.0 (#39)

BenchmarkGrok 4.1 FastMuse Spark
LMArena Text14081474
LMArena Creative Writing13941459
LMArena Multi-Turn13891477
EQ-Bench Creative Writing1327—

Frequently asked questions

Is Grok 4.1 Fast better than Muse Spark?

Muse Spark is the stronger model overall, scoring 50.6 to 41.4 on the Noometry Index.

Is Grok 4.1 Fast or Muse Spark better for coding?

Muse Spark scores higher on coding benchmarks: 46.2 versus 34.1 in the Noometry coding category.

How many benchmarks do Grok 4.1 Fast and Muse Spark share?

18 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Muse Spark has 27.

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