# Grok 4 Fast vs Muse Spark

> Muse Spark is the stronger model overall, scoring 50.6 to 39.4 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-4-fast-vs-muse-spark
- Last updated: 2026-10-10
- Shared benchmarks: 17

## Summary

- They share 17 benchmarks with published results for both. Grok 4 Fast scores higher in 1 category and Muse Spark in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Muse Spark leads 65.7 to 32.0.

## Snapshot

| | Grok 4 Fast | Muse Spark |
|---|---|---|
| Provider | xAI | Meta |
| Noometry Index | 39.4 | 50.6 |
| Rank | 167 | 46 |
| Context | — | — |
| Input $/M | — | — |
| Output $/M | — | — |
| Weights | Proprietary | Proprietary |

## Coding

- Grok 4 Fast: 32.5 (#271)
- Muse Spark: 46.2 (#69)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Coding | 1429 | 1481 |
| LMArena WebDev | 1159 | — |
| SciCode | — | 51.5% |
| WeirdML | 42.9% | — |

## Agentic & Tool Use

- Grok 4 Fast: 29.5 (#86)
- Muse Spark: —

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| τ²-bench Banking | 15.7% | — |
| Cybench | 30% | — |
| LMArena Search | 1171 | — |

## Reasoning

- Grok 4 Fast: 22.2 (#201)
- Muse Spark: 35.9 (#67)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Hard Prompts | 1412 | 1474 |
| Epoch Capabilities Index | 144.2 | 152.04 |
| ARC-AGI-2 | 5.3% | — |
| Kagi LLM Benchmark | 66.1% | — |
| ARC-AGI-1 | 48.5% | — |
| CritPt | — | 11.3% |
| DTBench | 82.7% | — |
| ForecastBench | 60.5 | — |

## Math

- Grok 4 Fast: 38.9 (#123)
- Muse Spark: 47.8 (#66)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Math | 1419 | 1455 |
| OTIS Mock AIME 2024-2025 | — | 88.9% |
| ProofBench | — | 17% |
| FrontierMath (Feb 2025 set) | — | 39% |
| FrontierMath Tier 4 (v1) | — | 14.6% |

## Knowledge

- Grok 4 Fast: 32.0 (#214)
- Muse Spark: 65.7 (#13)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Expert | 1411 | 1457 |
| GPQA Diamond | — | 89.8% |
| Humanity's Last Exam | — | 40.6% |
| Vectara Hallucination Rate | 19.7% | — |

## Multimodal

- Grok 4 Fast: —
- Muse Spark: 43.4 (#24)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Vision | — | 1306 |
| LMArena Document | — | 1444 |

## Multilingual

- Grok 4 Fast: 51.3 (#111)
- Muse Spark: 56.1 (#24)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Non-English | 1396 | 1464 |
| LMArena Chinese | 1457 | 1509 |
| LMArena French | 1431 | 1497 |
| LMArena German | 1383 | 1497 |
| LMArena Korean | 1357 | 1459 |
| LMArena Russian | 1389 | 1466 |
| LMArena Spanish | 1415 | 1472 |
| LMArena Japanese | 1352 | — |

## Instruction Following

- Grok 4 Fast: 73.2 (#121)
- Muse Spark: 75.9 (#51)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Instruction Following | 1387 | 1442 |

## Long Context

- Grok 4 Fast: 63.2 (#3)
- Muse Spark: 44.4 (#69)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Longer Query | 1415 | 1451 |
| Fiction.LiveBench | 94.4% | — |

## Writing & Preference

- Grok 4 Fast: 60.0 (#102)
- Muse Spark: 66.0 (#39)

| Benchmark | Grok 4 Fast | Muse Spark |
|---|---|---|
| LMArena Text | 1407 | 1474 |
| LMArena Creative Writing | 1387 | 1459 |
| LMArena Multi-Turn | 1414 | 1477 |

## FAQ

### Is Grok 4 Fast better than Muse Spark?

Muse Spark is the stronger model overall, scoring 50.6 to 39.4 on the Noometry Index.

### Is Grok 4 Fast or Muse Spark better for coding?

Muse Spark scores higher on coding benchmarks: 46.2 versus 32.5 in the Noometry coding category.

### How many benchmarks do Grok 4 Fast and Muse Spark share?

17 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Muse Spark has 27.