# Grok 4.1 Fast vs Mercury

> Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 37.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-4-1-fast-vs-mercury
- Last updated: 2026-10-10
- Shared benchmarks: 8

## Summary

- They share 8 benchmarks with published results for both. Grok 4.1 Fast scores higher in 5 categories and Mercury in 1 category; 6 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 17.5.

## Snapshot

| | Grok 4.1 Fast | Mercury |
|---|---|---|
| Provider | xAI | Inception |
| Noometry Index | 41.4 | 37.6 |
| Rank | 136 | 199 |
| Context | 128K | — |
| Input $/M | $0.20 | — |
| Output $/M | $0.50 | — |
| Weights | Proprietary | Proprietary |

## Coding

- Grok 4.1 Fast: 34.1 (#245)
- Mercury: 38.7 (#170)

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Coding | 1411 | 1322 |
| LMArena WebDev | 1242 | — |
| ALE-Bench | 394.93 | — |

## Agentic & Tool Use

- Grok 4.1 Fast: 36.3 (#39)
- Mercury: —

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

## Reasoning

- Grok 4.1 Fast: 43.4 (#49)
- Mercury: 17.5 (#293)

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Hard Prompts | 1407 | 1285 |
| SimpleBench | 56% | — |
| Kagi LLM Benchmark | — | 21.6% |
| NYT Connections (extended) | 87.4% | — |
| DTBench | 87.7% | — |
| ForecastBench | 61 | — |

## Math

- Grok 4.1 Fast: 31.9 (#221)
- Mercury: —

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

## Knowledge

- Grok 4.1 Fast: 33.1 (#207)
- Mercury: —

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| Vectara Hallucination Rate | 17.8% | — |
| LMArena Expert | 1399 | — |

## Multimodal

- Grok 4.1 Fast: 37.0 (#76)
- Mercury: —

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Vision | 1201 | — |

## Multilingual

- Grok 4.1 Fast: 51.0 (#114)
- Mercury: 41.6 (#206)

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Non-English | 1391 | 1260 |
| LMArena Chinese | 1441 | — |
| LMArena French | 1415 | — |
| LMArena German | 1404 | — |
| LMArena Japanese | 1349 | — |
| LMArena Korean | 1361 | — |
| LMArena Russian | 1387 | — |
| LMArena Spanish | 1413 | — |

## Instruction Following

- Grok 4.1 Fast: 72.7 (#133)
- Mercury: 65.2 (#224)

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Instruction Following | 1376 | 1239 |

## Long Context

- Grok 4.1 Fast: 42.4 (#126)
- Mercury: 38.4 (#198)

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Longer Query | 1390 | 1266 |

## Writing & Preference

- Grok 4.1 Fast: 57.2 (#131)
- Mercury: 46.2 (#221)

| Benchmark | Grok 4.1 Fast | Mercury |
|---|---|---|
| LMArena Text | 1408 | 1282 |
| LMArena Creative Writing | 1394 | 1191 |
| LMArena Multi-Turn | 1389 | 1282 |
| EQ-Bench Creative Writing | 1327 | — |

## FAQ

### Is Grok 4.1 Fast better than Mercury?

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 37.6 on the Noometry Index.

### Is Grok 4.1 Fast or Mercury better for coding?

Mercury scores higher on coding benchmarks: 38.7 versus 34.1 in the Noometry coding category.

### How many benchmarks do Grok 4.1 Fast and Mercury share?

8 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Mercury has 9.