Model comparison
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.
Last verified . 13 shared benchmarks.
Alibaba (Qwen)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.
Side by side
| Grok 4 Fast | Qwen1.5 4b Chat | |
|---|---|---|
| Provider | xAI | Alibaba (Qwen) |
| Noometry Index | 39.4 | 28.8 |
| Released | 2025-09-19 | — |
| Weights | Proprietary | Open |
| Context window | — | — |
| Max output | — | — |
| Input $ / M tokens | — | — |
| Output $ / M tokens | — | — |
| Results tracked | 30 | 13 |
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Category by category
Coding Grok 4 Fast leads
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 Not comparable
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 leads
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 leads
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 leads
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 leads
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 leads
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 leads
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 leads
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 |
Frequently asked questions
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.