# Grok 4 Fast vs Kimi K2.6

> Kimi K2.6 is the stronger model overall, scoring 47.5 to 39.0 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-4-fast-vs-kimi-k2-6
- Last updated: 2026-10-10
- Shared benchmarks: 22

## Summary

- They share 22 benchmarks with published results for both. Grok 4 Fast scores higher in 2 categories and Kimi K2.6 in 7 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Kimi K2.6 leads 53.9 to 31.5.
- The biggest single-benchmark swing is WeirdML: 42.9% for Grok 4 Fast and 55.9% for Kimi K2.6.
- Kimi K2.6 has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| Provider | xAI | Moonshot AI |
| Noometry Index | 39.0 | 47.5 |
| Rank | 164 | 52 |
| Context | — | 262K |
| Input $/M | — | $0.95 |
| Output $/M | — | $4 |
| Weights | Proprietary | Open |

## Coding

- Grok 4 Fast: 32.3 (#264)
- Kimi K2.6: 50.5 (#41)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena WebDev | 1160 | 1509 |
| WeirdML | 42.9% | 55.9% |
| LMArena Coding | 1429 | 1488 |
| SWE-bench Verified | — | 76.7% |
| SciCode | — | 53.5% |
| ALE-Bench | — | 1,093 |

## Agentic & Tool Use

- Grok 4 Fast: 29.3 (#80)
- Kimi K2.6: 21.8 (#128)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| OSWorld 2.0 | — | 4.6% |
| τ²-bench Banking | 15.7% | — |
| Cybench | 30% | — |
| ExploitBench | — | 18.4% |
| GBAEval | — | 0.9% |
| GDP.pdf | — | 12% |
| LMArena Search | 1171 | — |
| Vending-Bench 2 | — | 6,205 |

## Reasoning

- Grok 4 Fast: 22.5 (#179)
- Kimi K2.6: 39.6 (#51)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena Hard Prompts | 1413 | 1470 |
| DTBench | 82.7% | 90.9% |
| Epoch Capabilities Index | 144.21 | 151.03 |
| ARC-AGI-2 | 5.3% | — |
| Kagi LLM Benchmark | 66.1% | — |
| NYT Connections (extended) | — | 87.2% |
| ARC-AGI-1 | 48.5% | — |
| CritPt | — | 8% |
| Chess Puzzles | — | 26% |
| EBR-Bench | — | 2.4% |
| Mystery Game Puzzles | — | 18% |
| LMCA | — | 37.3% |
| ForecastBench | 60.5 | — |

## Math

- Grok 4 Fast: 36.1 (#126)
- Kimi K2.6: 56.8 (#34)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena Math | 1419 | 1475 |
| FrontierMath (Tiers 1-3) | — | 57.2% |
| FrontierMath Tier 4 | — | 25.6% |
| MathArena Final-Answer Competitions | — | 72.9% |
| OTIS Mock AIME 2024-2025 | — | 96.1% |
| ProofBench | — | 16% |
| FrontierMath (Feb 2025 set) | — | 39% |
| FrontierMath Tier 4 (v1) | — | 14.6% |

## Knowledge

- Grok 4 Fast: 31.5 (#211)
- Kimi K2.6: 53.9 (#48)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| Vectara Hallucination Rate | 19.7% | 10.8% |
| LMArena Expert | 1411 | 1491 |
| GPQA Diamond | — | 90.8% |
| SimpleQA Verified | — | 34.9% |

## Multimodal

- Grok 4 Fast: —
- Kimi K2.6: 31.8 (#95)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena Vision | — | 1282 |
| Blueprint-Bench 2 | — | 3.9% |
| Furniture Assembly | — | 21.7% |
| LMArena Document | — | 1451 |

## Multilingual

- Grok 4 Fast: 51.5 (#106)
- Kimi K2.6: 55.1 (#35)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena Non-English | 1397 | 1446 |
| LMArena Chinese | 1458 | 1521 |
| LMArena French | 1433 | 1471 |
| LMArena German | 1383 | 1449 |
| LMArena Japanese | 1358 | 1442 |
| LMArena Korean | 1359 | 1428 |
| LMArena Russian | 1387 | 1446 |
| LMArena Spanish | 1414 | 1463 |

## Instruction Following

- Grok 4 Fast: 73.4 (#116)
- Kimi K2.6: 76.5 (#40)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena Instruction Following | 1388 | 1451 |

## Long Context

- Grok 4 Fast: 63.2 (#3)
- Kimi K2.6: 44.9 (#50)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena Longer Query | 1415 | 1468 |
| Fiction.LiveBench | 94.4% | — |

## Writing & Preference

- Grok 4 Fast: 60.2 (#96)
- Kimi K2.6: 68.7 (#25)

| Benchmark | Grok 4 Fast | Kimi K2.6 |
|---|---|---|
| LMArena Text | 1407 | 1455 |
| LMArena Creative Writing | 1388 | 1434 |
| LMArena Multi-Turn | 1414 | 1453 |
| EQ-Bench Creative Writing | — | 1725 |
| EQ-Bench 4 | — | 1202 |

## FAQ

### Is Grok 4 Fast better than Kimi K2.6?

Kimi K2.6 is the stronger model overall, scoring 47.5 to 39.0 on the Noometry Index.

### Is Grok 4 Fast or Kimi K2.6 better for coding?

Kimi K2.6 scores higher on coding benchmarks: 50.5 versus 32.3 in the Noometry coding category.

### How many benchmarks do Grok 4 Fast and Kimi K2.6 share?

22 benchmarks have published results for both models. Grok 4 Fast has 30 scored results on Noometry and Kimi K2.6 has 51.