# GPT-5.1-Codex vs Mistral Nemo

> GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 25.9 on the Noometry Index. Mistral Nemo costs 23× less per token, which makes it the better buy when GPT-5.1-Codex's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-mistral-nemo
- Last updated: 2026-10-10
- Shared benchmarks: 0

## Summary

- The widest gap is in agentic & tool use, where GPT-5.1-Codex leads 37.8 to 23.3.
- Mistral Nemo is cheaper at $0.15 / $0.15 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- GPT-5.1-Codex accepts more context: 400K tokens versus 128K.
- Mistral Nemo has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | Mistral Nemo |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Noometry Index | 38.2 | 25.9 |
| Rank | 178 | 332 |
| Context | 400K | 128K |
| Input $/M | $1.25 | $0.15 |
| Output $/M | $10 | $0.15 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.7 (#107)
- Mistral Nemo: —

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

## Agentic & Tool Use

- GPT-5.1-Codex: 37.8 (#32)
- Mistral Nemo: 23.3 (#118)

| Benchmark | GPT-5.1-Codex | Mistral Nemo |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| Berkeley Function Calling Leaderboard | — | 27.6% |
| BALROG | — | 17.6% |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- Mistral Nemo: 19.9 (#230)

| Benchmark | GPT-5.1-Codex | Mistral Nemo |
|---|---|---|
| DTBench | — | 48.6% |
| Epoch Capabilities Index | — | 118.63 |
| PIQA | — | 83.5% |

## Math

- GPT-5.1-Codex: 29.3 (#218)
- Mistral Nemo: 23.5 (#263)

| Benchmark | GPT-5.1-Codex | Mistral Nemo |
|---|---|---|
| ProofBench | 9% | — |
| MATH Level 5 | — | 10.8% |
| GSM8K | — | 84.2% |

## Knowledge

- GPT-5.1-Codex: —
- Mistral Nemo: 12.3 (#293)

| Benchmark | GPT-5.1-Codex | Mistral Nemo |
|---|---|---|
| GPQA Diamond | — | 29.9% |
| BoolQ | — | 82.5% |

## Writing & Preference

- GPT-5.1-Codex: —
- Mistral Nemo: 28.6 (#291)

| Benchmark | GPT-5.1-Codex | Mistral Nemo |
|---|---|---|
| EQ-Bench Creative Writing | — | 881 |

## FAQ

### Is GPT-5.1-Codex better than Mistral Nemo?

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 25.9 on the Noometry Index. Mistral Nemo costs 23× less per token, which makes it the better buy when GPT-5.1-Codex's lead doesn't matter for your workload.

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

Mistral Nemo is cheaper. It lists at $0.15 per million input tokens and $0.15 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

### Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 128K.

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

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Mistral Nemo has 10.