# Grok 4 Fast vs Qwen1.5 4b Chat

> Grok 4 Fast is the stronger model overall, scoring 39.4 to 28.8 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-4-fast-vs-qwen1-5-4b-chat
- Last updated: 2026-10-10
- Shared benchmarks: 13

## Summary

- They share 13 benchmarks with published results for both. Grok 4 Fast scores higher in 8 categories and Qwen1.5 4b Chat in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Grok 4 Fast leads 60.0 to 23.8.
- Qwen1.5 4b Chat has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| Provider | xAI | Alibaba (Qwen) |
| Noometry Index | 39.4 | 28.8 |
| Rank | 167 | 322 |
| Context | — | — |
| Input $/M | — | — |
| Output $/M | — | — |
| Weights | Proprietary | Open |

## Coding

- Grok 4 Fast: 32.5 (#271)
- Qwen1.5 4b Chat: 29.1 (#308)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Coding | 1429 | 999 |
| LMArena WebDev | 1159 | — |
| WeirdML | 42.9% | — |

## Agentic & Tool Use

- Grok 4 Fast: 29.5 (#86)
- Qwen1.5 4b Chat: —

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| τ²-bench Banking | 15.7% | — |
| Cybench | 30% | — |
| LMArena Search | 1171 | — |

## Reasoning

- Grok 4 Fast: 22.2 (#201)
- Qwen1.5 4b Chat: 18.5 (#279)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Hard Prompts | 1412 | 976 |
| ARC-AGI-2 | 5.3% | — |
| Kagi LLM Benchmark | 66.1% | — |
| ARC-AGI-1 | 48.5% | — |
| DTBench | 82.7% | — |
| Epoch Capabilities Index | 144.2 | — |
| ForecastBench | 60.5 | — |

## Math

- Grok 4 Fast: 38.9 (#123)
- Qwen1.5 4b Chat: 30.4 (#234)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Math | 1419 | 1026 |

## Knowledge

- Grok 4 Fast: 32.0 (#214)
- Qwen1.5 4b Chat: 26.7 (#255)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Expert | 1411 | 980 |
| Vectara Hallucination Rate | 19.7% | — |

## Multilingual

- Grok 4 Fast: 51.3 (#111)
- Qwen1.5 4b Chat: 24.1 (#290)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Non-English | 1396 | 979 |
| LMArena Chinese | 1457 | 1024 |
| LMArena German | 1383 | 902 |
| LMArena Russian | 1389 | 952 |
| LMArena French | 1431 | — |
| LMArena Japanese | 1352 | — |
| LMArena Korean | 1357 | — |
| LMArena Spanish | 1415 | — |

## Instruction Following

- Grok 4 Fast: 73.2 (#121)
- Qwen1.5 4b Chat: 49.0 (#300)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Instruction Following | 1387 | 978 |

## Long Context

- Grok 4 Fast: 63.2 (#3)
- Qwen1.5 4b Chat: 30.1 (#290)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Longer Query | 1415 | 988 |
| Fiction.LiveBench | 94.4% | — |

## Writing & Preference

- Grok 4 Fast: 60.0 (#102)
- Qwen1.5 4b Chat: 23.8 (#309)

| Benchmark | Grok 4 Fast | Qwen1.5 4b Chat |
|---|---|---|
| LMArena Text | 1407 | 997 |
| LMArena Creative Writing | 1387 | 969 |
| LMArena Multi-Turn | 1414 | 977 |

## FAQ

### Is Grok 4 Fast better than Qwen1.5 4b Chat?

Grok 4 Fast is the stronger model overall, scoring 39.4 to 28.8 on the Noometry Index.

### Is Grok 4 Fast or Qwen1.5 4b Chat better for coding?

Grok 4 Fast scores higher on coding benchmarks: 32.5 versus 29.1 in the Noometry coding category.

### How many benchmarks do Grok 4 Fast and Qwen1.5 4b Chat share?

13 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Qwen1.5 4b Chat has 13.