# Grok 4.1 Fast vs Phi 3 Mini 4k Instruct

> Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 27.4 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-4-1-fast-vs-phi-3-mini-4k-instruct
- Last updated: 2026-10-10
- Shared benchmarks: 17

## Summary

- They share 17 benchmarks with published results for both. Grok 4.1 Fast scores higher in 8 categories and Phi 3 Mini 4k Instruct in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Grok 4.1 Fast leads 57.4 to 27.7.
- Phi 3 Mini 4k Instruct has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| Provider | xAI | Microsoft |
| Noometry Index | 40.9 | 27.4 |
| Rank | 131 | 324 |
| Context | 128K | — |
| Input $/M | $0.20 | — |
| Output $/M | $0.50 | — |
| Weights | Proprietary | Open |

## Coding

- Grok 4.1 Fast: 33.8 (#236)
- Phi 3 Mini 4k Instruct: 26.1 (#319)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Coding | 1411 | 1093 |
| LMArena WebDev | 1241 | — |
| LiveBench Coding | — | 15.5% |
| ALE-Bench | 394.93 | — |
| HumanEval+ | — | 59.1% |
| MBPP+ | — | 54.2% |

## Agentic & Tool Use

- Grok 4.1 Fast: 36.1 (#35)
- Phi 3 Mini 4k Instruct: —

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| 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)
- Phi 3 Mini 4k Instruct: 13.6 (#326)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Hard Prompts | 1407 | 1072 |
| SimpleBench | 56% | — |
| NYT Connections (extended) | 87.4% | — |
| Chess Puzzles | — | 0% |
| LiveBench Reasoning | — | 26.8% |
| DTBench | 87.7% | — |
| LiveBench Data Analysis | — | 34.7% |
| Adversarial NLI | — | 52.8% |
| BIG-Bench Hard | — | 71.7% |
| ForecastBench | 61 | — |
| HellaSwag | — | 76.7% |
| LiveBench | — | 22.4% |
| WinoGrande | — | 70.8% |

## Math

- Grok 4.1 Fast: 30.9 (#201)
- Phi 3 Mini 4k Instruct: 24.5 (#258)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Math | 1408 | 1111 |
| MathArena Final-Answer Competitions | 60.9% | — |
| ProofBench | 4% | — |
| LiveBench Math | — | 15.7% |

## Knowledge

- Grok 4.1 Fast: 32.6 (#203)
- Phi 3 Mini 4k Instruct: 27.9 (#241)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Expert | 1398 | 1045 |
| Vectara Hallucination Rate | 17.8% | — |
| ARC (AI2) Challenge | — | 84.9% |
| MMLU | — | 68.8% |
| OpenBookQA | — | 88% |
| TriviaQA | — | 64% |

## Multimodal

- Grok 4.1 Fast: 36.3 (#71)
- Phi 3 Mini 4k Instruct: —

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Vision | 1201 | — |

## Multilingual

- Grok 4.1 Fast: 51.1 (#110)
- Phi 3 Mini 4k Instruct: 26.5 (#275)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Non-English | 1391 | 1021 |
| LMArena Chinese | 1441 | 1021 |
| LMArena French | 1416 | 1075 |
| LMArena German | 1404 | 1044 |
| LMArena Japanese | 1347 | 935 |
| LMArena Korean | 1361 | 905 |
| LMArena Russian | 1387 | 1022 |
| LMArena Spanish | 1411 | 1084 |

## Instruction Following

- Grok 4.1 Fast: 72.8 (#127)
- Phi 3 Mini 4k Instruct: 48.0 (#298)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Instruction Following | 1376 | 1053 |
| LiveBench Instruction Following | — | 39.1% |

## Long Context

- Grok 4.1 Fast: 42.4 (#121)
- Phi 3 Mini 4k Instruct: 31.7 (#271)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Longer Query | 1390 | 1044 |

## Writing & Preference

- Grok 4.1 Fast: 57.4 (#126)
- Phi 3 Mini 4k Instruct: 27.7 (#295)

| Benchmark | Grok 4.1 Fast | Phi 3 Mini 4k Instruct |
|---|---|---|
| LMArena Text | 1408 | 1073 |
| LMArena Creative Writing | 1394 | 1037 |
| LMArena Multi-Turn | 1389 | 1018 |
| EQ-Bench Creative Writing | 1327 | — |
| LiveBench Language | — | 9.2% |

## FAQ

### Is Grok 4.1 Fast better than Phi 3 Mini 4k Instruct?

Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 27.4 on the Noometry Index.

### Is Grok 4.1 Fast or Phi 3 Mini 4k Instruct better for coding?

Grok 4.1 Fast scores higher on coding benchmarks: 33.8 versus 26.1 in the Noometry coding category.

### How many benchmarks do Grok 4.1 Fast and Phi 3 Mini 4k Instruct share?

17 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Phi 3 Mini 4k Instruct has 35.