# GPT-5.3 Codex vs Mistral Nemo

> GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 26.4 on the Noometry Index. Mistral Nemo costs 32× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-5-3-codex-vs-mistral-nemo
- Last updated: 2026-10-12
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5.3 Codex scores higher in 1 category and Mistral Nemo in 0 categories; one gap is clear of the uncertainty.
- The widest gap is in agentic & tool use, where GPT-5.3 Codex leads 48.0 to 23.5.
- Mistral Nemo is cheaper at $0.15 / $0.15 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- GPT-5.3 Codex accepts more context: 400K tokens versus 128K.
- Mistral Nemo has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Codex | Mistral Nemo |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Noometry Index | 45.8 | 26.4 |
| Rank | 69 | 337 |
| Context | 400K | 128K |
| Input $/M | $1.75 | $0.15 |
| Output $/M | $14 | $0.15 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Codex: 48.6 (#56)
- Mistral Nemo: —

| Benchmark | GPT-5.3 Codex | Mistral Nemo |
|---|---|---|
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| WeirdML | 79.3% | — |
| ALE-Bench | 1,655 | — |

## Agentic & Tool Use

- GPT-5.3 Codex: 48.0 (#9)
- Mistral Nemo: 23.5 (#125)

| Benchmark | GPT-5.3 Codex | Mistral Nemo |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| Berkeley Function Calling Leaderboard | — | 27.6% |
| BALROG | — | 17.6% |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |

## Reasoning

- GPT-5.3 Codex: —
- Mistral Nemo: 20.7 (#232)

| Benchmark | GPT-5.3 Codex | Mistral Nemo |
|---|---|---|
| Epoch Capabilities Index | 156.77 | 118.68 |
| DTBench | — | 48.6% |
| PIQA | — | 83.5% |

## Math

- GPT-5.3 Codex: —
- Mistral Nemo: 25.5 (#268)

| Benchmark | GPT-5.3 Codex | Mistral Nemo |
|---|---|---|
| MATH Level 5 | — | 10.8% |
| GSM8K | — | 84.2% |

## Knowledge

- GPT-5.3 Codex: —
- Mistral Nemo: 12.3 (#298)

| Benchmark | GPT-5.3 Codex | Mistral Nemo |
|---|---|---|
| GPQA Diamond | — | 29.9% |
| BoolQ | — | 82.5% |

## Writing & Preference

- GPT-5.3 Codex: —
- Mistral Nemo: 28.5 (#296)

| Benchmark | GPT-5.3 Codex | Mistral Nemo |
|---|---|---|
| EQ-Bench Creative Writing | — | 881 |

## FAQ

### Is GPT-5.3 Codex better than Mistral Nemo?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 26.4 on the Noometry Index. Mistral Nemo costs 32× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

### Which is cheaper, GPT-5.3 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-5.3 Codex lists at $1.75 and $14.

### Which has the bigger context window?

GPT-5.3 Codex does, with 400K tokens against 128K.

### How many benchmarks do GPT-5.3 Codex and Mistral Nemo share?

1 benchmark has published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Mistral Nemo has 10.