# Grok 4.1 Fast vs Muse Glimmer

> Grok 4.1 Fast and Muse Glimmer score almost the same on the Noometry Index (40.9 vs 41.3), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/grok-4-1-fast-vs-muse-glimmer
- Last updated: 2026-10-10
- Shared benchmarks: 13

## Summary

- They share 13 benchmarks with published results for both. Grok 4.1 Fast scores higher in 4 categories and Muse Glimmer in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 42.3 to 27.2.
- Muse Glimmer has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| Provider | xAI | Meta |
| Noometry Index | 40.9 | 41.3 |
| Rank | 131 | 128 |
| Context | 128K | — |
| Input $/M | $0.20 | — |
| Output $/M | $0.50 | — |
| Weights | Proprietary | Open |

## Coding

- Grok 4.1 Fast: 33.8 (#236)
- Muse Glimmer: 38.7 (#157)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena WebDev | 1241 | 1355 |
| LMArena Coding | 1411 | 1417 |
| ALE-Bench | 394.93 | — |

## Agentic & Tool Use

- Grok 4.1 Fast: 36.1 (#35)
- Muse Glimmer: —

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| Berkeley Function Calling Leaderboard | 69.6% | — |
| τ²-bench Banking | 13.1% | — |
| LMArena Search | 1171 | — |
| Vending-Bench 2 | 1,107 | — |

## Reasoning

- Grok 4.1 Fast: 42.3 (#45)
- Muse Glimmer: 27.2 (#111)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Hard Prompts | 1407 | 1395 |
| SimpleBench | 56% | — |
| NYT Connections (extended) | 87.4% | — |
| DTBench | 87.7% | — |
| ForecastBench | 61 | — |

## Math

- Grok 4.1 Fast: 30.9 (#201)
- Muse Glimmer: 36.1 (#128)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Math | 1408 | 1419 |
| MathArena Final-Answer Competitions | 60.9% | — |
| ProofBench | 4% | — |

## Knowledge

- Grok 4.1 Fast: 32.6 (#203)
- Muse Glimmer: 37.9 (#140)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Expert | 1398 | 1388 |
| Vectara Hallucination Rate | 17.8% | — |

## Multimodal

- Grok 4.1 Fast: 36.3 (#71)
- Muse Glimmer: —

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Vision | 1201 | — |

## Multilingual

- Grok 4.1 Fast: 51.1 (#110)
- Muse Glimmer: 50.6 (#117)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Non-English | 1391 | 1384 |
| LMArena Chinese | 1441 | 1412 |
| LMArena Russian | 1387 | 1393 |
| LMArena French | 1416 | — |
| LMArena German | 1404 | — |
| LMArena Japanese | 1347 | — |
| LMArena Korean | 1361 | — |
| LMArena Spanish | 1411 | — |

## Instruction Following

- Grok 4.1 Fast: 72.8 (#127)
- Muse Glimmer: 72.7 (#134)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Instruction Following | 1376 | 1374 |

## Long Context

- Grok 4.1 Fast: 42.4 (#121)
- Muse Glimmer: 42.1 (#124)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Longer Query | 1390 | 1381 |

## Writing & Preference

- Grok 4.1 Fast: 57.4 (#126)
- Muse Glimmer: 57.7 (#122)

| Benchmark | Grok 4.1 Fast | Muse Glimmer |
|---|---|---|
| LMArena Text | 1408 | 1389 |
| LMArena Creative Writing | 1394 | 1338 |
| LMArena Multi-Turn | 1389 | 1398 |
| EQ-Bench Creative Writing | 1327 | — |

## FAQ

### Is Grok 4.1 Fast better than Muse Glimmer?

Grok 4.1 Fast and Muse Glimmer score almost the same on the Noometry Index (40.9 vs 41.3), so choose on price, context window or the category you care about most.

### Is Grok 4.1 Fast or Muse Glimmer better for coding?

Muse Glimmer scores higher on coding benchmarks: 38.7 versus 33.8 in the Noometry coding category.

### How many benchmarks do Grok 4.1 Fast and Muse Glimmer share?

13 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Muse Glimmer has 13.