# Grok 4.5 vs Kimi K2.5 Instant

> Grok 4.5 is the stronger model overall, scoring 55.0 to 43.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-4-5-vs-kimi-k2-5-instant
- Last updated: 2026-10-12
- Shared benchmarks: 18

## Summary

- They share 18 benchmarks with published results for both. Grok 4.5 scores higher in 8 categories and Kimi K2.5 Instant in 1 category; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.5 leads 56.1 to 29.7.
- Kimi K2.5 Instant has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| Provider | xAI | Moonshot AI |
| Noometry Index | 55.0 | 43.6 |
| Rank | 25 | 89 |
| Context | 500K | — |
| Input $/M | $2 | — |
| Output $/M | $6 | — |
| Weights | Proprietary | Open |

## Coding

- Grok 4.5: 52.2 (#35)
- Kimi K2.5 Instant: 42.6 (#97)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena WebDev | 1553 | 1404 |
| LMArena Coding | 1474 | 1484 |
| DeepSWE | 53.8% | — |
| FrontierCode | 42.4% | — |
| SciCode | 54.1% | — |
| WeirdML | 46.4% | — |
| ALE-Bench | 1,309 | — |

## Agentic & Tool Use

- Grok 4.5: 44.4 (#17)
- Kimi K2.5 Instant: —

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| APEX-Agents | 56.2% | — |
| τ²-bench Banking | 47.9% | — |
| PostTrainBench | 23.4% | — |
| GBAEval | 65.4% | — |
| GDP.pdf | 14% | — |
| LMArena Search | 1213 | — |
| Vending-Bench 2 | 3,887 | — |

## Reasoning

- Grok 4.5: 56.1 (#25)
- Kimi K2.5 Instant: 29.7 (#90)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Hard Prompts | 1462 | 1443 |
| ARC-AGI-2 | 52.6% | — |
| SimpleBench | 70% | — |
| Kagi LLM Benchmark | 83.5% | — |
| NYT Connections (extended) | 79.9% | — |
| ARC-AGI-1 | 87.2% | — |
| CritPt | 15.4% | — |
| Chess Puzzles | 36% | — |
| DTBench | 96.5% | — |
| LMCA | 45.2% | — |
| Surface Evolver Bench | 74.4% | — |
| Epoch Capabilities Index | 153.92 | — |

## Math

- Grok 4.5: 60.9 (#35)
- Kimi K2.5 Instant: 39.4 (#105)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Math | 1459 | 1442 |
| FrontierMath (Tiers 1-3) | 57.2% | — |
| FrontierMath Tier 4 | 24.4% | — |
| OTIS Mock AIME 2024-2025 | 97.8% | — |
| ProofBench | 31% | — |

## Knowledge

- Grok 4.5: 62.3 (#24)
- Kimi K2.5 Instant: 40.2 (#123)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Expert | 1466 | 1440 |
| GPQA Diamond | 93.4% | — |
| SimpleQA Verified | 48.3% | — |

## Multimodal

- Grok 4.5: 37.6 (#72)
- Kimi K2.5 Instant: 40.2 (#50)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Vision | 1288 | 1254 |
| Blueprint-Bench 2 | 27.3% | — |
| Furniture Assembly | 22.5% | — |
| LMArena Document | 1452 | — |

## Multilingual

- Grok 4.5: 54.4 (#42)
- Kimi K2.5 Instant: 52.0 (#94)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Non-English | 1440 | 1406 |
| LMArena Chinese | 1496 | 1449 |
| LMArena French | 1456 | 1403 |
| LMArena German | 1446 | 1413 |
| LMArena Korean | 1404 | 1378 |
| LMArena Russian | 1448 | 1404 |
| LMArena Spanish | 1450 | 1447 |
| LMArena Japanese | 1428 | — |

## Instruction Following

- Grok 4.5: 76.0 (#48)
- Kimi K2.5 Instant: 75.3 (#65)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1446 | 1430 |

## Long Context

- Grok 4.5: 44.8 (#56)
- Kimi K2.5 Instant: 43.9 (#83)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Longer Query | 1463 | 1435 |

## Writing & Preference

- Grok 4.5: 65.8 (#42)
- Kimi K2.5 Instant: 60.6 (#95)

| Benchmark | Grok 4.5 | Kimi K2.5 Instant |
|---|---|---|
| LMArena Text | 1448 | 1420 |
| LMArena Creative Writing | 1442 | 1381 |
| LMArena Multi-Turn | 1456 | 1427 |
| EQ-Bench Creative Writing | 1579 | — |

## FAQ

### Is Grok 4.5 better than Kimi K2.5 Instant?

Grok 4.5 is the stronger model overall, scoring 55.0 to 43.6 on the Noometry Index.

### Is Grok 4.5 or Kimi K2.5 Instant better for coding?

Grok 4.5 scores higher on coding benchmarks: 52.2 versus 42.6 in the Noometry coding category.

### How many benchmarks do Grok 4.5 and Kimi K2.5 Instant share?

18 benchmarks have published results for both models. Grok 4.5 has 52 scored results on Noometry and Kimi K2.5 Instant has 18.