# Gemma 4 31B IT vs GPT-5.3 Codex

> GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 43.2 on the Noometry Index. Gemma 4 31B IT 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/gemma-4-31b-it-vs-gpt-5-3-codex
- Last updated: 2026-10-10
- Shared benchmarks: 4

## Summary

- They share 4 benchmarks with published results for both. Gemma 4 31B IT scores higher in 0 categories and GPT-5.3 Codex in 1 category; one gap is clear of the uncertainty.
- The widest gap is in coding, where GPT-5.3 Codex leads 48.5 to 41.9.
- The biggest single-benchmark swing is WeirdML: 52.3% for Gemma 4 31B IT and 79.3% for GPT-5.3 Codex.
- Gemma 4 31B IT is cheaper at $0.09 / $0.34 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.
- Gemma 4 31B IT has downloadable open weights; the other is API-only.

## Snapshot

| | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 43.2 | 45.5 |
| Rank | 85 | 61 |
| Context | 262K | 400K |
| Input $/M | $0.09 | $1.75 |
| Output $/M | $0.34 | $14 |
| Weights | Open | Proprietary |

## Coding

- Gemma 4 31B IT: 41.9 (#98)
- GPT-5.3 Codex: 48.5 (#51)

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| LMArena WebDev | 1364 | 1408 |
| WeirdML | 52.3% | 79.3% |
| ALE-Bench | 925.5 | 1,655 |
| SWE-bench Verified | — | 74.8% |
| SciCode | 43.4% | — |
| LMArena Coding | 1459 | — |

## Agentic & Tool Use

- Gemma 4 31B IT: —
- GPT-5.3 Codex: 47.8 (#9)

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| Terminal-Bench | — | 78.4% |
| METR Time Horizons | — | 74.5% |
| Vending-Bench 2 | — | 5,940 |

## Reasoning

- Gemma 4 31B IT: 26.4 (#119)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| Epoch Capabilities Index | 142.74 | 156.84 |
| Kagi LLM Benchmark | 63.5% | — |
| NYT Connections (extended) | 70.6% | — |
| CritPt | 1.4% | — |
| Chess Puzzles | 5% | — |
| Thematic Generalization | 53% | — |
| LMArena Hard Prompts | 1448 | — |
| DTBench | 82.7% | — |
| LMCA | 39.3% | — |
| Surface Evolver Bench | 30.6% | — |

## Math

- Gemma 4 31B IT: 41.3 (#72)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 73.3% | — |
| LMArena Math | 1464 | — |

## Knowledge

- Gemma 4 31B IT: 37.9 (#141)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| GPQA Diamond | 75.8% | — |
| SimpleQA Verified | 10.4% | — |
| Vectara Hallucination Rate | 7.4% | — |
| LMArena Expert | 1465 | — |

## Multimodal

- Gemma 4 31B IT: 41.0 (#32)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| LMArena Vision | 1278 | — |
| LMArena Document | 1425 | — |

## Multilingual

- Gemma 4 31B IT: 54.0 (#52)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| LMArena Non-English | 1431 | — |
| LMArena Chinese | 1478 | — |
| LMArena French | 1436 | — |
| LMArena Russian | 1462 | — |
| LMArena Spanish | 1443 | — |

## Instruction Following

- Gemma 4 31B IT: 75.6 (#58)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| LMArena Instruction Following | 1433 | — |

## Long Context

- Gemma 4 31B IT: 44.2 (#67)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| LMArena Longer Query | 1446 | — |

## Writing & Preference

- Gemma 4 31B IT: 60.7 (#92)
- GPT-5.3 Codex: —

| Benchmark | Gemma 4 31B IT | GPT-5.3 Codex |
|---|---|---|
| LMArena Text | 1443 | — |
| LMArena Creative Writing | 1416 | — |
| EQ-Bench Creative Writing | 1368 | — |
| EQ-Bench 4 | 1120 | — |
| LMArena Multi-Turn | 1452 | — |

## FAQ

### Is Gemma 4 31B IT better than GPT-5.3 Codex?

GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 43.2 on the Noometry Index. Gemma 4 31B IT 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, Gemma 4 31B IT or GPT-5.3 Codex?

Gemma 4 31B IT is cheaper. It lists at $0.09 per million input tokens and $0.34 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

### Is Gemma 4 31B IT or GPT-5.3 Codex better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.5 versus 41.9 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 Gemma 4 31B IT and GPT-5.3 Codex share?

4 benchmarks have published results for both models. Gemma 4 31B IT has 35 scored results on Noometry and GPT-5.3 Codex has 8.