# Grok 4.1 Fast vs Phi-4 Mini

> Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 30.9 on the Noometry Index. Phi-4 Mini costs 2.1× less per token, which makes it the better buy when Grok 4.1 Fast's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/grok-4-1-fast-vs-phi-4-mini
- Last updated: 2026-10-12
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. Grok 4.1 Fast scores higher in 3 categories and Phi-4 Mini in 0 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 22.4.
- The biggest single-benchmark swing is Vectara Hallucination Rate: 17.8% for Grok 4.1 Fast and 23.5% for Phi-4 Mini.
- Phi-4 Mini is cheaper at $0.075 / $0.30 per million input/output tokens, against $0.20 / $0.50 for Grok 4.1 Fast.
- Phi-4 Mini has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| Provider | xAI | Microsoft |
| Noometry Index | 41.4 | 30.9 |
| Rank | 136 | 283 |
| Context | 128K | 128K |
| Input $/M | $0.20 | $0.075 |
| Output $/M | $0.50 | $0.30 |
| Weights | Proprietary | Open |

## Coding

- Grok 4.1 Fast: 34.1 (#245)
- Phi-4 Mini: 28.1 (#317)

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| LMArena WebDev | 1242 | — |
| SciCode | — | 10.8% |
| LMArena Coding | 1411 | — |
| ALE-Bench | 394.93 | — |

## Agentic & Tool Use

- Grok 4.1 Fast: 36.3 (#39)
- Phi-4 Mini: —

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| 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)
- Phi-4 Mini: 22.4 (#195)

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| SimpleBench | 56% | — |
| NYT Connections (extended) | 87.4% | — |
| CritPt | — | 0% |
| LMArena Hard Prompts | 1407 | — |
| DTBench | 87.7% | — |
| ForecastBench | 61 | — |

## Math

- Grok 4.1 Fast: 31.9 (#221)
- Phi-4 Mini: —

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

## Knowledge

- Grok 4.1 Fast: 33.1 (#207)
- Phi-4 Mini: 25.3 (#262)

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| Vectara Hallucination Rate | 17.8% | 23.5% |
| LMArena Expert | 1399 | — |

## Multimodal

- Grok 4.1 Fast: 37.0 (#76)
- Phi-4 Mini: —

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

## Multilingual

- Grok 4.1 Fast: 51.0 (#114)
- Phi-4 Mini: —

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| LMArena Non-English | 1391 | — |
| 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)
- Phi-4 Mini: —

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| LMArena Instruction Following | 1376 | — |

## Long Context

- Grok 4.1 Fast: 42.4 (#126)
- Phi-4 Mini: —

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| LMArena Longer Query | 1390 | — |

## Writing & Preference

- Grok 4.1 Fast: 57.2 (#131)
- Phi-4 Mini: —

| Benchmark | Grok 4.1 Fast | Phi-4 Mini |
|---|---|---|
| LMArena Text | 1408 | — |
| LMArena Creative Writing | 1394 | — |
| EQ-Bench Creative Writing | 1327 | — |
| LMArena Multi-Turn | 1389 | — |

## FAQ

### Is Grok 4.1 Fast better than Phi-4 Mini?

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 30.9 on the Noometry Index. Phi-4 Mini costs 2.1× less per token, which makes it the better buy when Grok 4.1 Fast's lead doesn't matter for your workload.

### Which is cheaper, Grok 4.1 Fast or Phi-4 Mini?

Phi-4 Mini is cheaper. It lists at $0.075 per million input tokens and $0.30 per million output tokens; Grok 4.1 Fast lists at $0.20 and $0.50.

### Is Grok 4.1 Fast or Phi-4 Mini better for coding?

Grok 4.1 Fast scores higher on coding benchmarks: 34.1 versus 28.1 in the Noometry coding category.

### Which has the bigger context window?

Both accept 128K tokens.

### How many benchmarks do Grok 4.1 Fast and Phi-4 Mini share?

1 benchmark has published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Phi-4 Mini has 3.