# Kimi K3 vs o3

> Kimi K3 is the stronger model overall, scoring 59.5 to 47.5 on the Noometry Index. o3 costs 1.7× less per token, which makes it the better buy when Kimi K3's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/kimi-k3-vs-o3
- Last updated: 2026-10-11
- Shared benchmarks: 34

## Summary

- They share 34 benchmarks with published results for both. Kimi K3 scores higher in 8 categories and o3 in 2 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Kimi K3 leads 63.0 to 32.0.
- The biggest single-benchmark swing is ARC-AGI-2: 60.4% for Kimi K3 and 6.5% for o3.
- o3 is cheaper at $2 / $8 per million input/output tokens, against $3 / $15 for Kimi K3.
- Kimi K3 accepts more context: 1.05M tokens versus 200K.
- Kimi K3 has downloadable open weights; the other is API-only.

## Snapshot

| | Kimi K3 | o3 |
|---|---|---|
| Provider | Moonshot AI | OpenAI |
| Noometry Index | 59.5 | 47.5 |
| Rank | 15 | 61 |
| Context | 1.05M | 200K |
| Input $/M | $3 | $2 |
| Output $/M | $15 | $8 |
| Weights | Open | Proprietary |

## Coding

- Kimi K3: 61.0 (#10)
- o3: 46.8 (#64)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| WeirdML | 82.6% | 52.4% |
| LMArena Coding | 1508 | 1408 |
| ALE-Bench | 1,524 | 933.55 |
| SWE-bench Verified | — | 62.3% |
| DeepSWE | 68.5% | — |
| FrontierCode | 44.2% | — |
| SWE-bench Verified (bash only) | — | 58.4% |
| Aider Polyglot | — | 81.3% |
| LMArena WebDev | 1654 | — |
| FrontierSWE | 25.9% | — |
| SciCode | 59.5% | — |
| GSO | — | 8.8% |
| CadEval | — | 74% |

## Agentic & Tool Use

- Kimi K3: 41.8 (#20)
- o3: 34.5 (#44)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| APEX-Agents | 50.6% | — |
| Berkeley Function Calling Leaderboard | — | 63% |
| GDPval | — | 30.8% |
| τ²-bench Banking | 37.1% | — |
| DeepResearch Bench | — | 45.2% |
| OSWorld | — | 23% |
| PostTrainBench | 32% | — |
| GBAEval | 48.3% | — |
| GDP.pdf | 19% | — |
| LMArena Search | — | 1144 |
| METR Time Horizons | — | 65.4% |
| Vending-Bench 2 | 5,165 | — |

## Reasoning

- Kimi K3: 63.0 (#17)
- o3: 32.0 (#78)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| ARC-AGI-2 | 60.4% | 6.5% |
| SimpleBench | 60.7% | 53.1% |
| ARC-AGI-1 | 94.5% | 60.8% |
| CritPt | 23.4% | 1.4% |
| Chess Puzzles | 39% | 38% |
| LMArena Hard Prompts | 1496 | 1402 |
| Mystery Game Puzzles | 26% | 29% |
| DTBench | 91.2% | 84.8% |
| LMCA | 52.7% | 39.7% |
| Epoch Capabilities Index | 157.45 | 146.86 |
| ForecastBench | 61.1 | 62.5 |
| Kagi LLM Benchmark | — | 67.6% |
| NYT Connections (extended) | 93.6% | — |
| EnigmaEval | — | 13.1% |
| Surface Evolver Bench | 95% | — |

## Math

- Kimi K3: 74.2 (#16)
- o3: 50.2 (#58)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 72.2% | 33.3% |
| OTIS Mock AIME 2024-2025 | 97.2% | 84.4% |
| LMArena Math | 1491 | 1426 |
| FrontierMath Tier 4 | 39% | — |
| MathArena Final-Answer Competitions | 87.8% | — |
| ProofBench | 87% | — |
| Omni-MATH | — | 71.4% |
| MATH Level 5 | — | 97.8% |
| FrontierMath (Feb 2025 set) | — | 18.7% |
| FrontierMath Tier 4 (v1) | — | 2.1% |

## Knowledge

- Kimi K3: 63.2 (#21)
- o3: 54.6 (#52)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| GPQA Diamond | 93.1% | 81.8% |
| SimpleQA Verified | 50.6% | 49.4% |
| LMArena Expert | 1521 | 1402 |
| Humanity's Last Exam | — | 20.3% |
| MMLU-Pro | — | 85.9% |
| Confabulations | — | 14.4% |
| GPQA (HELM) | — | 75.3% |

## Multimodal

- Kimi K3: 37.8 (#70)
- o3: 41.4 (#36)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| LMArena Vision | — | 1214 |
| GeoBench | — | 74% |
| VPCT | — | 52% |
| Blueprint-Bench 2 | 29.5% | — |
| Furniture Assembly | 34.2% | — |

## Multilingual

- Kimi K3: 56.3 (#21)
- o3: 51.7 (#105)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| LMArena Non-English | 1466 | 1401 |
| LMArena Chinese | 1529 | 1437 |
| LMArena French | 1491 | 1430 |
| LMArena German | 1488 | 1420 |
| LMArena Japanese | 1487 | 1403 |
| LMArena Korean | 1458 | 1370 |
| LMArena Russian | 1482 | 1406 |
| LMArena Spanish | 1472 | 1395 |

## Instruction Following

- Kimi K3: 77.7 (#14)
- o3: 72.8 (#127)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| LMArena Instruction Following | 1483 | 1368 |
| IFEval | — | 86.9% |

## Long Context

- Kimi K3: 45.8 (#29)
- o3: 53.3 (#6)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| LMArena Longer Query | 1494 | 1372 |
| Fiction.LiveBench | — | 88.9% |
| CL-bench | — | 17.8% |

## Writing & Preference

- Kimi K3: 76.6 (#4)
- o3: 63.5 (#64)

| Benchmark | Kimi K3 | o3 |
|---|---|---|
| LMArena Text | 1476 | 1410 |
| LMArena Creative Writing | 1454 | 1359 |
| EQ-Bench Creative Writing | 2082 | 1676 |
| LMArena Multi-Turn | 1488 | 1405 |
| Short-Story Creative Writing | — | 83.9% |
| WildBench | — | 86.1% |
| EQ-Bench 4 | 1339 | — |

## FAQ

### Is Kimi K3 better than o3?

Kimi K3 is the stronger model overall, scoring 59.5 to 47.5 on the Noometry Index. o3 costs 1.7× less per token, which makes it the better buy when Kimi K3's lead doesn't matter for your workload.

### Which is cheaper, Kimi K3 or o3?

o3 is cheaper. It lists at $2 per million input tokens and $8 per million output tokens; Kimi K3 lists at $3 and $15.

### Is Kimi K3 or o3 better for coding?

Kimi K3 scores higher on coding benchmarks: 61.0 versus 46.8 in the Noometry coding category.

### Which has the bigger context window?

Kimi K3 does, with 1.05M tokens against 200K.

### How many benchmarks do Kimi K3 and o3 share?

34 benchmarks have published results for both models. Kimi K3 has 53 scored results on Noometry and o3 has 63.