# GPT-5.1-Codex vs Kimi K2 Thinking Turbo

> Kimi K2 Thinking Turbo is the stronger model overall, scoring 45.8 to 38.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-kimi-k2-thinking-turbo
- Last updated: 2026-10-12
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5.1-Codex scores higher in 1 category and Kimi K2 Thinking Turbo in 1 category; 2 gaps are clear of the uncertainty.
- The widest gap is in math, where Kimi K2 Thinking Turbo leads 47.4 to 30.3.
- Kimi K2 Thinking Turbo has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Noometry Index | 38.6 | 45.8 |
| Rank | 186 | 70 |
| Context | 400K | — |
| Input $/M | $1.25 | — |
| Output $/M | $10 | — |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.9 (#116)
- Kimi K2 Thinking Turbo: 38.4 (#178)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena WebDev | 1337 | 1322 |
| SWE-bench Verified (bash only) | 66% | — |
| LMArena Coding | — | 1454 |
| ALE-Bench | 1,245 | — |

## Agentic & Tool Use

- GPT-5.1-Codex: 38.0 (#33)
- Kimi K2 Thinking Turbo: —

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- Kimi K2 Thinking Turbo: 32.5 (#75)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| Chess Puzzles | — | 20% |
| LMArena Hard Prompts | — | 1428 |

## Math

- GPT-5.1-Codex: 30.3 (#235)
- Kimi K2 Thinking Turbo: 47.4 (#68)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 83.1% |
| ProofBench | 9% | — |
| LMArena Math | — | 1429 |

## Knowledge

- GPT-5.1-Codex: —
- Kimi K2 Thinking Turbo: 50.9 (#69)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| GPQA Diamond | — | 84.2% |
| LMArena Expert | — | 1439 |

## Multilingual

- GPT-5.1-Codex: —
- Kimi K2 Thinking Turbo: 51.4 (#109)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Non-English | — | 1398 |
| LMArena Chinese | — | 1456 |
| LMArena French | — | 1425 |
| LMArena German | — | 1390 |
| LMArena Japanese | — | 1357 |
| LMArena Korean | — | 1330 |
| LMArena Russian | — | 1391 |
| LMArena Spanish | — | 1406 |

## Instruction Following

- GPT-5.1-Codex: —
- Kimi K2 Thinking Turbo: 74.0 (#109)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Instruction Following | — | 1403 |

## Long Context

- GPT-5.1-Codex: —
- Kimi K2 Thinking Turbo: 43.2 (#102)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Longer Query | — | 1415 |

## Writing & Preference

- GPT-5.1-Codex: —
- Kimi K2 Thinking Turbo: 60.0 (#104)

| Benchmark | GPT-5.1-Codex | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Text | — | 1415 |
| LMArena Creative Writing | — | 1374 |
| LMArena Multi-Turn | — | 1414 |

## FAQ

### Is GPT-5.1-Codex better than Kimi K2 Thinking Turbo?

Kimi K2 Thinking Turbo is the stronger model overall, scoring 45.8 to 38.6 on the Noometry Index.

### Is GPT-5.1-Codex or Kimi K2 Thinking Turbo better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 38.4 in the Noometry coding category.

### How many benchmarks do GPT-5.1-Codex and Kimi K2 Thinking Turbo share?

1 benchmark has published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Kimi K2 Thinking Turbo has 21.