# Grok 4 Fast vs MiMo-V2.5-Pro

> MiMo-V2.5-Pro is the stronger model overall, scoring 45.2 to 39.4 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-4-fast-vs-mimo-v2-5-pro
- Last updated: 2026-10-10
- Shared benchmarks: 19

## Summary

- They share 19 benchmarks with published results for both. Grok 4 Fast scores higher in 1 category and MiMo-V2.5-Pro in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in long context, where Grok 4 Fast leads 63.2 to 45.4.
- MiMo-V2.5-Pro has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| Provider | xAI | Xiaomi |
| Noometry Index | 39.4 | 45.2 |
| Rank | 167 | 74 |
| Context | — | 1.05M |
| Input $/M | — | $0.43 |
| Output $/M | — | $0.87 |
| Weights | Proprietary | Open |

## Coding

- Grok 4 Fast: 32.5 (#271)
- MiMo-V2.5-Pro: 47.4 (#60)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena WebDev | 1159 | 1479 |
| LMArena Coding | 1429 | 1503 |
| SciCode | — | 50.2% |
| WeirdML | 42.9% | — |
| ALE-Bench | — | 899.8 |

## Agentic & Tool Use

- Grok 4 Fast: 29.5 (#86)
- MiMo-V2.5-Pro: —

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| τ²-bench Banking | 15.7% | — |
| Cybench | 30% | — |
| LMArena Search | 1171 | — |

## Reasoning

- Grok 4 Fast: 22.2 (#201)
- MiMo-V2.5-Pro: 26.8 (#130)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Hard Prompts | 1412 | 1488 |
| DTBench | 82.7% | 84.5% |
| ARC-AGI-2 | 5.3% | — |
| Kagi LLM Benchmark | 66.1% | — |
| NYT Connections (extended) | — | 34.4% |
| ARC-AGI-1 | 48.5% | — |
| CritPt | — | 4% |
| LMCA | — | 29.5% |
| Epoch Capabilities Index | 144.2 | — |
| ForecastBench | 60.5 | — |

## Math

- Grok 4 Fast: 38.9 (#123)
- MiMo-V2.5-Pro: 40.0 (#96)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Math | 1419 | 1481 |
| ProofBench | — | 22% |

## Knowledge

- Grok 4 Fast: 32.0 (#214)
- MiMo-V2.5-Pro: 42.2 (#98)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Expert | 1411 | 1503 |
| Vectara Hallucination Rate | 19.7% | — |

## Multilingual

- Grok 4 Fast: 51.3 (#111)
- MiMo-V2.5-Pro: 55.1 (#34)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Non-English | 1396 | 1449 |
| LMArena Chinese | 1457 | 1507 |
| LMArena French | 1431 | 1488 |
| LMArena German | 1383 | 1458 |
| LMArena Japanese | 1352 | 1412 |
| LMArena Korean | 1357 | 1437 |
| LMArena Russian | 1389 | 1450 |
| LMArena Spanish | 1415 | 1471 |

## Instruction Following

- Grok 4 Fast: 73.2 (#121)
- MiMo-V2.5-Pro: 77.5 (#21)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Instruction Following | 1387 | 1477 |

## Long Context

- Grok 4 Fast: 63.2 (#3)
- MiMo-V2.5-Pro: 45.4 (#37)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Longer Query | 1415 | 1483 |
| Fiction.LiveBench | 94.4% | — |

## Writing & Preference

- Grok 4 Fast: 60.0 (#102)
- MiMo-V2.5-Pro: 65.3 (#49)

| Benchmark | Grok 4 Fast | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Text | 1407 | 1465 |
| LMArena Creative Writing | 1387 | 1440 |
| LMArena Multi-Turn | 1414 | 1477 |
| EQ-Bench Creative Writing | — | 1493 |
| EQ-Bench 4 | — | 1208 |

## FAQ

### Is Grok 4 Fast better than MiMo-V2.5-Pro?

MiMo-V2.5-Pro is the stronger model overall, scoring 45.2 to 39.4 on the Noometry Index.

### Is Grok 4 Fast or MiMo-V2.5-Pro better for coding?

MiMo-V2.5-Pro scores higher on coding benchmarks: 47.4 versus 32.5 in the Noometry coding category.

### How many benchmarks do Grok 4 Fast and MiMo-V2.5-Pro share?

19 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and MiMo-V2.5-Pro has 27.