# Grok-2 (Dec 2024) vs Grok 4.1 Fast

> Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 33.7 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-2-vs-grok-4-1-fast
- Last updated: 2026-10-10
- Shared benchmarks: 19

## Summary

- They share 19 benchmarks with published results for both. Grok-2 (Dec 2024) scores higher in 0 categories and Grok 4.1 Fast in 8 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 16.9.
- The biggest single-benchmark swing is SimpleBench: 22.7% for Grok-2 (Dec 2024) and 56% for Grok 4.1 Fast.

## Snapshot

| | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| Provider | xAI | xAI |
| Noometry Index | 33.7 | 41.4 |
| Rank | 239 | 136 |
| Context | — | 128K |
| Input $/M | — | $0.20 |
| Output $/M | — | $0.50 |
| Weights | Proprietary | Proprietary |

## Coding

- Grok-2 (Dec 2024): 33.3 (#258)
- Grok 4.1 Fast: 34.1 (#245)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Coding | 1287 | 1411 |
| LMArena WebDev | — | 1242 |
| WeirdML | 22.2% | — |
| LiveBench Coding | 46.4% | — |
| ALE-Bench | — | 394.93 |

## Agentic & Tool Use

- Grok-2 (Dec 2024): —
- Grok 4.1 Fast: 36.3 (#39)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| LMArena Search | — | 1171 |
| Vending-Bench 2 | — | 1,107 |

## Reasoning

- Grok-2 (Dec 2024): 16.9 (#299)
- Grok 4.1 Fast: 43.4 (#49)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| SimpleBench | 22.7% | 56% |
| LMArena Hard Prompts | 1272 | 1407 |
| DTBench | 65.2% | 87.7% |
| NYT Connections (extended) | — | 87.4% |
| LiveBench Reasoning | 54.8% | — |
| LiveBench Data Analysis | 54.5% | — |
| Epoch Capabilities Index | 130.48 | — |
| ForecastBench | — | 61 |
| LiveBench | 54.3% | — |

## Math

- Grok-2 (Dec 2024): 20.8 (#284)
- Grok 4.1 Fast: 31.9 (#221)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Math | 1283 | 1408 |
| MathArena Final-Answer Competitions | — | 60.9% |
| OTIS Mock AIME 2024-2025 | 11.5% | — |
| ProofBench | — | 4% |
| LiveBench Math | 54.9% | — |
| MATH Level 5 | 63.5% | — |
| FrontierMath (Feb 2025 set) | 0.7% | — |

## Knowledge

- Grok-2 (Dec 2024): 29.8 (#233)
- Grok 4.1 Fast: 33.1 (#207)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Expert | 1254 | 1399 |
| GPQA Diamond | 53.8% | — |
| Confabulations | 20.1% | — |
| Vectara Hallucination Rate | — | 17.8% |

## Multimodal

- Grok-2 (Dec 2024): —
- Grok 4.1 Fast: 37.0 (#76)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |

## Multilingual

- Grok-2 (Dec 2024): 43.1 (#188)
- Grok 4.1 Fast: 51.0 (#114)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | 1282 | 1391 |
| LMArena Chinese | 1289 | 1441 |
| LMArena French | 1318 | 1415 |
| LMArena German | 1287 | 1404 |
| LMArena Japanese | 1244 | 1349 |
| LMArena Korean | 1237 | 1361 |
| LMArena Russian | 1286 | 1387 |
| LMArena Spanish | 1281 | 1413 |

## Instruction Following

- Grok-2 (Dec 2024): 66.9 (#202)
- Grok 4.1 Fast: 72.7 (#133)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | 1270 | 1376 |
| LiveBench Instruction Following | 69.6% | — |

## Long Context

- Grok-2 (Dec 2024): 38.8 (#190)
- Grok 4.1 Fast: 42.4 (#126)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | 1276 | 1390 |

## Writing & Preference

- Grok-2 (Dec 2024): 48.6 (#198)
- Grok 4.1 Fast: 57.2 (#131)

| Benchmark | Grok-2 (Dec 2024) | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | 1305 | 1408 |
| LMArena Creative Writing | 1284 | 1394 |
| LMArena Multi-Turn | 1290 | 1389 |
| Short-Story Creative Writing | 63.6% | — |
| EQ-Bench Creative Writing | — | 1327 |
| LiveBench Language | 45.6% | — |

## FAQ

### Is Grok-2 (Dec 2024) better than Grok 4.1 Fast?

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 33.7 on the Noometry Index.

### Is Grok-2 (Dec 2024) or Grok 4.1 Fast better for coding?

They score almost the same on coding (33.3 vs 34.1); test both on your own repository before choosing.

### How many benchmarks do Grok-2 (Dec 2024) and Grok 4.1 Fast share?

19 benchmarks have published results for both models. Grok-2 (Dec 2024) has 34 scored results on Noometry and Grok 4.1 Fast has 32.