# Gemma 4 31B vs GPT-5.3 Codex

> Side-by-side benchmark comparison for Gemma 4 31B and GPT-5.3 Codex across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemma-4-31b-vs-gpt-5-3-codex
- Last updated: October 6, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Gemma 4 31B and GPT-5.3 Codex share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Gemma 4 31B has the lower published output-token price.
- GPT-5.3 Codex has the larger published context window at 400K.

## Model Snapshot

| Property | Gemma 4 31B | GPT-5.3 Codex |
|----------|----------|----------|
| Creator | Google | OpenAI |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 256K | 400K |
| Independent public score (not head-to-head) | 40.49 | 60.85 |
| Benchmarks Covered | 8 | 10 |
| Pricing (input/output) | $0.00 / $0.00 | $1.75 / $14.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 19.1 (Estimated · #101/120)
- GPT-5.3 Codex public-lane score: 55.2 (Estimated · #34/120)

| Benchmark | Gemma 4 31B | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 35.26% | 57.47% | GPT-5.3 Codex |
| Terminal-Bench 2.0 | Coming soon | 77.3% | Coming soon |
| OSWorld-Verified | Coming soon | 64.7% | Coming soon |
| JobBench | Coming soon | 33.7% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 33.2 (Supported · #85/144)
- GPT-5.3 Codex public-lane score: 55.8 (Supported · #28/144)

| Benchmark | Gemma 4 31B | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| SWE-Rebench | 41.6% | 58.2% | GPT-5.3 Codex |
| React Native Evals | 75.2% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 85% | Coming soon |
| SWE-bench Pro | Coming soon | 56.8% | Coming soon |
| Vibe Code Bench | Coming soon | 61.77% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 87.3% | Coming soon |
| SWE-bench (Vals) | Coming soon | 78.0% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 70.2 (Unranked · 2 rankable rows)
- GPT-5.3 Codex public-lane score: 79.6 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 59.5 (#31/49)
- GPT-5.3 Codex public-lane score: 76.7 (Unranked · 1 rankable row)

| Benchmark | Gemma 4 31B | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 76.9% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 38.6 (Supported · #107/173)
- GPT-5.3 Codex public-lane score: 64.3 (Estimated · #27/173)

| Benchmark | Gemma 4 31B | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 84.3% | Coming soon | Coming soon |
| MMLU-Pro | 85.2% | Coming soon | Coming soon |
| HLE | 26.5% | Coming soon | Coming soon |
| HLE w/o tools | 19.5% | Coming soon | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 91.5 (#13/125)
- GPT-5.3 Codex public-lane score: 91.2 (#14/125)

## FAQ

### Is there enough evidence to pick between Gemma 4 31B and GPT-5.3 Codex?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Gemma 4 31B vs Gemma 4 26B A4B](/compare/gemma-4-26b-a4b-vs-gemma-4-31b)
- [GPT-5.3 Codex vs Gemma 4 26B A4B](/compare/gemma-4-26b-a4b-vs-gpt-5-3-codex)
- [Gemma 4 31B vs Gemma 4 12B](/compare/gemma-4-12b-vs-gemma-4-31b)
- [GPT-5.3 Codex vs Gemma 4 12B](/compare/gemma-4-12b-vs-gpt-5-3-codex)

## Explore More

- [Gemma 4 31B profile](/models/gemma-4-31b)
- [GPT-5.3 Codex profile](/models/gpt-5-3-codex)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)