# Gemma 3 27B vs GPT-5.1-Codex

> GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 30.8 on the Noometry Index. Gemma 3 27B costs 34× 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/gemma-3-27b-vs-gpt-5-1-codex
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where GPT-5.1-Codex leads 41.9 to 22.5.
- Gemma 3 27B is cheaper at $0.08 / $0.16 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- GPT-5.1-Codex accepts more context: 400K tokens versus 131K.
- Gemma 3 27B has downloadable open weights; the other is API-only.

## Snapshot

| | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 30.8 | 38.6 |
| Rank | 284 | 186 |
| Context | 131K | 400K |
| Input $/M | $0.08 | $1.25 |
| Output $/M | $0.16 | $10 |
| Weights | Open | Proprietary |

## Coding

- Gemma 3 27B: 22.5 (#334)
- GPT-5.1-Codex: 41.9 (#116)

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| SWE-bench Verified (bash only) | — | 66% |
| Aider Polyglot | 4.9% | — |
| LMArena WebDev | — | 1337 |
| SciCode | 21.2% | — |
| LiveBench Coding | 39.9% | — |
| LMArena Coding | 1322 | — |
| ALE-Bench | — | 1,245 |

## Agentic & Tool Use

- Gemma 3 27B: 25.1 (#110)
- GPT-5.1-Codex: 38.0 (#33)

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| Terminal-Bench | — | 60.4% |
| Berkeley Function Calling Leaderboard | 29.5% | — |
| METR Time Horizons | — | 70.8% |

## Reasoning

- Gemma 3 27B: 16.7 (#301)
- GPT-5.1-Codex: —

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| Kagi LLM Benchmark | 40.4% | — |
| CritPt | 0% | — |
| Chess Puzzles | 0% | — |
| LiveBench Reasoning | 43.8% | — |
| LMArena Hard Prompts | 1340 | — |
| DTBench | 52.5% | — |
| LiveBench Data Analysis | 51.5% | — |
| LMCA | 12.3% | — |
| Epoch Capabilities Index | 130.04 | — |
| LiveBench | 50% | — |

## Math

- Gemma 3 27B: 25.9 (#265)
- GPT-5.1-Codex: 30.3 (#235)

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 22.5% | — |
| ProofBench | — | 9% |
| LiveBench Math | 55.4% | — |
| LMArena Math | 1312 | — |
| MATH Level 5 | 74% | — |

## Knowledge

- Gemma 3 27B: 25.5 (#261)
- GPT-5.1-Codex: —

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| GPQA Diamond | 47.7% | — |
| Confabulations | 40.3% | — |
| Vectara Hallucination Rate | 7.4% | — |
| LMArena Expert | 1304 | — |

## Multimodal

- Gemma 3 27B: 32.6 (#100)
- GPT-5.1-Codex: —

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| LMArena Vision | 1164 | — |
| GeoBench | 52% | — |

## Multilingual

- Gemma 3 27B: 46.9 (#155)
- GPT-5.1-Codex: —

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| LMArena Non-English | 1334 | — |
| LMArena Chinese | 1346 | — |
| LMArena French | 1368 | — |
| LMArena German | 1362 | — |
| LMArena Japanese | 1287 | — |
| LMArena Korean | 1308 | — |
| LMArena Russian | 1349 | — |
| LMArena Spanish | 1349 | — |

## Instruction Following

- Gemma 3 27B: 70.6 (#160)
- GPT-5.1-Codex: —

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| LiveBench Instruction Following | 74.9% | — |
| LMArena Instruction Following | 1321 | — |

## Long Context

- Gemma 3 27B: 27.6 (#293)
- GPT-5.1-Codex: —

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| Fiction.LiveBench | 33.3% | — |
| LMArena Longer Query | 1333 | — |

## Writing & Preference

- Gemma 3 27B: 52.5 (#168)
- GPT-5.1-Codex: —

| Benchmark | Gemma 3 27B | GPT-5.1-Codex |
|---|---|---|
| LMArena Text | 1358 | — |
| LMArena Creative Writing | 1346 | — |
| Short-Story Creative Writing | 79.9% | — |
| EQ-Bench Creative Writing | 1266 | — |
| LMArena Multi-Turn | 1345 | — |
| LiveBench Language | 34.6% | — |

## FAQ

### Is Gemma 3 27B better than GPT-5.1-Codex?

GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 30.8 on the Noometry Index. Gemma 3 27B costs 34× 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, Gemma 3 27B or GPT-5.1-Codex?

Gemma 3 27B is cheaper. It lists at $0.08 per million input tokens and $0.16 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

### Is Gemma 3 27B or GPT-5.1-Codex better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 22.5 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 131K.

### How many benchmarks do Gemma 3 27B and GPT-5.1-Codex share?

0 benchmarks have published results for both models. Gemma 3 27B has 43 scored results on Noometry and GPT-5.1-Codex has 6.