# GPT-5.1-Codex vs Mistral Large 3

> GPT-5.1-Codex and Mistral Large 3 score almost the same on the Noometry Index (38.2 vs 38.6), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-mistral-large-3
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5.1-Codex scores higher in 1 category and Mistral Large 3 in 1 category; 2 gaps are clear of the uncertainty.
- The widest gap is in coding, where GPT-5.1-Codex leads 41.7 to 34.1.
- Mistral Large 3 is cheaper at $0.25 / $0.75 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- GPT-5.1-Codex accepts more context: 400K tokens versus 262K.
- Mistral Large 3 has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Noometry Index | 38.2 | 38.6 |
| Rank | 178 | 172 |
| Context | 400K | 262K |
| Input $/M | $1.25 | $0.25 |
| Output $/M | $10 | $0.75 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.7 (#107)
- Mistral Large 3: 34.1 (#230)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| LMArena WebDev | 1337 | 1230 |
| SWE-bench Verified (bash only) | 66% | — |
| LMArena Coding | — | 1447 |
| ALE-Bench | 1,245 | — |

## Agentic & Tool Use

- GPT-5.1-Codex: 37.8 (#32)
- Mistral Large 3: —

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- Mistral Large 3: 14.6 (#314)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| Kagi LLM Benchmark | — | 50.9% |
| NYT Connections (extended) | — | 7.5% |
| Thematic Generalization | — | 23% |
| LMArena Hard Prompts | — | 1429 |

## Math

- GPT-5.1-Codex: 29.3 (#218)
- Mistral Large 3: 36.0 (#131)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| ProofBench | 9% | — |
| LMArena Math | — | 1415 |

## Knowledge

- GPT-5.1-Codex: —
- Mistral Large 3: 35.5 (#173)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| Vectara Hallucination Rate | — | 14.5% |
| LMArena Expert | — | 1421 |

## Multimodal

- GPT-5.1-Codex: —
- Mistral Large 3: 37.6 (#65)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| LMArena Vision | — | 1222 |

## Multilingual

- GPT-5.1-Codex: —
- Mistral Large 3: 52.6 (#79)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| LMArena Non-English | — | 1412 |
| LMArena Chinese | — | 1448 |
| LMArena French | — | 1456 |
| LMArena German | — | 1438 |
| LMArena Japanese | — | 1399 |
| LMArena Korean | — | 1384 |
| LMArena Russian | — | 1412 |
| LMArena Spanish | — | 1437 |

## Instruction Following

- GPT-5.1-Codex: —
- Mistral Large 3: 74.1 (#104)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| LMArena Instruction Following | — | 1402 |

## Long Context

- GPT-5.1-Codex: —
- Mistral Large 3: 43.1 (#102)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| LMArena Longer Query | — | 1413 |

## Writing & Preference

- GPT-5.1-Codex: —
- Mistral Large 3: 60.2 (#100)

| Benchmark | GPT-5.1-Codex | Mistral Large 3 |
|---|---|---|
| LMArena Text | — | 1427 |
| LMArena Creative Writing | — | 1385 |
| EQ-Bench Creative Writing | — | 1412 |
| LMArena Multi-Turn | — | 1429 |

## FAQ

### Is GPT-5.1-Codex better than Mistral Large 3?

GPT-5.1-Codex and Mistral Large 3 score almost the same on the Noometry Index (38.2 vs 38.6), so choose on price, context window or the category you care about most.

### Which is cheaper, GPT-5.1-Codex or Mistral Large 3?

Mistral Large 3 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

### Is GPT-5.1-Codex or Mistral Large 3 better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.7 versus 34.1 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 262K.

### How many benchmarks do GPT-5.1-Codex and Mistral Large 3 share?

1 benchmark has published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Mistral Large 3 has 24.