Model comparison

Grok 4.1 Fast vs Muse Spark 1.3

Muse Spark 1.3 is the stronger model overall, scoring 54.4 to 40.9 on the Noometry Index. Grok 4.1 Fast costs 7.3× less per token, which makes it the better buy when Muse Spark 1.3's lead doesn't matter for your workload.

Last verified . 20 shared benchmarks.

Grok 4.1 Fast xAI

40.9

Rank #131 Confirmed

Muse Spark 1.3 Meta

54.4

Rank #27 Confirmed

Summary

  • They share 20 benchmarks with published results for both. Grok 4.1 Fast scores higher in 0 categories and Muse Spark 1.3 in 10 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Muse Spark 1.3 leads 72.4 to 30.9.
  • The biggest single-benchmark swing is DTBench: 87.7% for Grok 4.1 Fast and 96.5% for Muse Spark 1.3.
  • Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $1.25 / $4.25 for Muse Spark 1.3.
  • Muse Spark 1.3 accepts more context: 1.05M tokens versus 128K.

Side by side

Grok 4.1 Fast and Muse Spark 1.3 specifications
Grok 4.1 FastMuse Spark 1.3
ProviderxAIMeta
Noometry Index40.954.4
Released2025-06-272026-09-02
WeightsProprietaryProprietary
Context window128K1.05M
Max output30K131K
Input $ / M tokens$0.20$1.25
Output $ / M tokens$0.50$4.25
Results tracked3234

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Category by category

Coding Muse Spark 1.3 leads

Grok 4.1 Fast: 33.8 (#236), Muse Spark 1.3: 56.1 (#18)

Coding benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena WebDev12411655
LMArena Coding14111516
CursorBench—41.6%
SciCode—59.7%
ALE-Bench394.93—

Agentic & Tool Use Muse Spark 1.3 leads

Grok 4.1 Fast: 36.1 (#35), Muse Spark 1.3: 38.6 (#28)

Agentic & Tool Use benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
APEX-Agents—57.8%
Berkeley Function Calling Leaderboard69.6%—
τ²-bench Banking13.1%—
GDP.pdf—27.6%
LMArena Search1171—
Vending-Bench 21,107—

Reasoning Muse Spark 1.3 leads

Grok 4.1 Fast: 42.3 (#45), Muse Spark 1.3: 52.9 (#27)

Reasoning benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
NYT Connections (extended)87.4%85.1%
LMArena Hard Prompts14071503
DTBench87.7%96.5%
SimpleBench56%—
CritPt—24.9%
Chess Puzzles—38%
Mystery Game Puzzles—25%
LMCA—53.9%
Bench to the Future 3—0.14
Epoch Capabilities Index—156.89
ForecastBench61—

Math Muse Spark 1.3 leads

Grok 4.1 Fast: 30.9 (#201), Muse Spark 1.3: 72.4 (#16)

Math benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena Math14081497
FrontierMath (Tiers 1-3)—74.4%
FrontierMath Tier 4—46.3%
MathArena Final-Answer Competitions60.9%—
OTIS Mock AIME 2024-2025—99.2%
ProofBench4%—

Knowledge Muse Spark 1.3 leads

Grok 4.1 Fast: 32.6 (#203), Muse Spark 1.3: 42.0 (#92)

Knowledge benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena Expert13981516
Vectara Hallucination Rate17.8%—

Multimodal Muse Spark 1.3 leads

Grok 4.1 Fast: 36.3 (#71), Muse Spark 1.3: 43.0 (#21)

Multimodal benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena Vision12011310
LMArena Document—1471

Multilingual Muse Spark 1.3 leads

Grok 4.1 Fast: 51.1 (#110), Muse Spark 1.3: 57.8 (#6)

Multilingual benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena Non-English13911485
LMArena Chinese14411527
LMArena French14161534
LMArena Korean13611513
LMArena Russian13871491
LMArena Spanish14111485
LMArena German1404—
LMArena Japanese1347—

Instruction Following Muse Spark 1.3 leads

Grok 4.1 Fast: 72.8 (#127), Muse Spark 1.3: 77.8 (#14)

Instruction Following benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena Instruction Following13761481

Long Context Muse Spark 1.3 leads

Grok 4.1 Fast: 42.4 (#121), Muse Spark 1.3: 45.7 (#29)

Long Context benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena Longer Query13901491

Writing & Preference Muse Spark 1.3 leads

Grok 4.1 Fast: 57.4 (#126), Muse Spark 1.3: 73.7 (#10)

Writing & Preference benchmarks
BenchmarkGrok 4.1 FastMuse Spark 1.3
LMArena Text14081490
LMArena Creative Writing13941450
EQ-Bench Creative Writing13271906
LMArena Multi-Turn13891486

Frequently asked questions

Is Grok 4.1 Fast better than Muse Spark 1.3?

Muse Spark 1.3 is the stronger model overall, scoring 54.4 to 40.9 on the Noometry Index. Grok 4.1 Fast costs 7.3× less per token, which makes it the better buy when Muse Spark 1.3's lead doesn't matter for your workload.

Which is cheaper, Grok 4.1 Fast or Muse Spark 1.3?

Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; Muse Spark 1.3 lists at $1.25 and $4.25.

Is Grok 4.1 Fast or Muse Spark 1.3 better for coding?

Muse Spark 1.3 scores higher on coding benchmarks: 56.1 versus 33.8 in the Noometry coding category.

Which has the bigger context window?

Muse Spark 1.3 does, with 1.05M tokens against 128K.

How many benchmarks do Grok 4.1 Fast and Muse Spark 1.3 share?

20 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Muse Spark 1.3 has 34.

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