# GPT-5.3 Codex vs Nemotron 3.5 Lightning

> GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 40.0 on the Noometry Index. Nemotron 3.5 Lightning costs 55× 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-nemotron-3-5-lightning
- Last updated: 2026-10-12
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where GPT-5.3 Codex leads 48.6 to 40.4.
- Nemotron 3.5 Lightning is cheaper at $0.05 / $0.20 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- GPT-5.3 Codex accepts more context: 400K tokens versus 262K.
- Nemotron 3.5 Lightning has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| Provider | OpenAI | NVIDIA |
| Noometry Index | 45.8 | 40.0 |
| Rank | 69 | 155 |
| Context | 400K | 262K |
| Input $/M | $1.75 | $0.05 |
| Output $/M | $14 | $0.20 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Codex: 48.6 (#56)
- Nemotron 3.5 Lightning: 40.4 (#141)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| WeirdML | 79.3% | — |
| LMArena Coding | — | 1375 |
| ALE-Bench | 1,655 | — |

## Agentic & Tool Use

- GPT-5.3 Codex: 48.0 (#9)
- Nemotron 3.5 Lightning: —

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |

## Reasoning

- GPT-5.3 Codex: —
- Nemotron 3.5 Lightning: 26.8 (#127)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Hard Prompts | — | 1337 |
| Epoch Capabilities Index | 156.77 | — |

## Math

- GPT-5.3 Codex: —
- Nemotron 3.5 Lightning: 37.5 (#155)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Math | — | 1359 |

## Knowledge

- GPT-5.3 Codex: —
- Nemotron 3.5 Lightning: 37.5 (#154)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Expert | — | 1356 |

## Multilingual

- GPT-5.3 Codex: —
- Nemotron 3.5 Lightning: 44.0 (#180)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Non-English | — | 1295 |
| LMArena Chinese | — | 1359 |
| LMArena French | — | 1366 |
| LMArena German | — | 1282 |
| LMArena Japanese | — | 1206 |
| LMArena Korean | — | 1238 |
| LMArena Russian | — | 1253 |
| LMArena Spanish | — | 1345 |

## Instruction Following

- GPT-5.3 Codex: —
- Nemotron 3.5 Lightning: 69.6 (#170)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Instruction Following | — | 1318 |

## Long Context

- GPT-5.3 Codex: —
- Nemotron 3.5 Lightning: 39.9 (#165)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Longer Query | — | 1314 |

## Writing & Preference

- GPT-5.3 Codex: —
- Nemotron 3.5 Lightning: 48.5 (#201)

| Benchmark | GPT-5.3 Codex | Nemotron 3.5 Lightning |
|---|---|---|
| LMArena Text | — | 1327 |
| LMArena Creative Writing | — | 1254 |
| EQ-Bench Creative Writing | — | 1280 |
| LMArena Multi-Turn | — | 1328 |

## FAQ

### Is GPT-5.3 Codex better than Nemotron 3.5 Lightning?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 40.0 on the Noometry Index. Nemotron 3.5 Lightning costs 55× 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 Nemotron 3.5 Lightning?

Nemotron 3.5 Lightning is cheaper. It lists at $0.05 per million input tokens and $0.20 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

### Is GPT-5.3 Codex or Nemotron 3.5 Lightning better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 40.4 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.3 Codex does, with 400K tokens against 262K.

### How many benchmarks do GPT-5.3 Codex and Nemotron 3.5 Lightning share?

0 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Nemotron 3.5 Lightning has 18.