# Gemma 2 27B vs GPT-5.1-Codex

> GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 29.4 on the Noometry Index. Gemma 2 27B costs 5.3× 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-2-27b-vs-gpt-5-1-codex
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in math, where GPT-5.1-Codex leads 30.3 to 10.7.
- Gemma 2 27B is cheaper at $0.65 / $0.65 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- GPT-5.1-Codex accepts more context: 400K tokens versus 8K.
- Gemma 2 27B has downloadable open weights; the other is API-only.

## Snapshot

| | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 29.4 | 38.6 |
| Rank | 312 | 186 |
| Context | 8K | 400K |
| Input $/M | $0.65 | $1.25 |
| Output $/M | $0.65 | $10 |
| Weights | Open | Proprietary |

## Coding

- Gemma 2 27B: 34.1 (#246)
- GPT-5.1-Codex: 41.9 (#116)

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| SWE-bench Verified (bash only) | — | 66% |
| LMArena WebDev | — | 1337 |
| BigCodeBench Instruct | 42.8% | — |
| LiveBench Coding | 36% | — |
| LMArena Coding | 1211 | — |
| BigCodeBench Complete | 52.5% | — |
| ALE-Bench | — | 1,245 |

## Agentic & Tool Use

- Gemma 2 27B: —
- GPT-5.1-Codex: 38.0 (#33)

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| Terminal-Bench | — | 60.4% |
| METR Time Horizons | — | 70.8% |

## Reasoning

- Gemma 2 27B: 15.3 (#315)
- GPT-5.1-Codex: —

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| LiveBench Reasoning | 28.1% | — |
| LMArena Hard Prompts | 1198 | — |
| DTBench | 48% | — |
| LiveBench Data Analysis | 47.9% | — |
| LMCA | 7.1% | — |
| Epoch Capabilities Index | 122.08 | — |
| LiveBench | 38.2% | — |

## Math

- Gemma 2 27B: 10.7 (#311)
- GPT-5.1-Codex: 30.3 (#235)

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.4% | — |
| ProofBench | — | 9% |
| LiveBench Math | 26.5% | — |
| LMArena Math | 1212 | — |
| MATH Level 5 | 27.9% | — |

## Knowledge

- Gemma 2 27B: 19.0 (#280)
- GPT-5.1-Codex: —

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| GPQA Diamond | 36.5% | — |
| Confabulations | 27.1% | — |
| LMArena Expert | 1172 | — |
| MMLU | 75.7% | — |

## Multilingual

- Gemma 2 27B: 38.6 (#226)
- GPT-5.1-Codex: —

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| LMArena Non-English | 1217 | — |
| LMArena Chinese | 1221 | — |
| LMArena French | 1247 | — |
| LMArena German | 1209 | — |
| LMArena Japanese | 1175 | — |
| LMArena Korean | 1174 | — |
| LMArena Russian | 1234 | — |
| LMArena Spanish | 1228 | — |

## Instruction Following

- Gemma 2 27B: 60.5 (#249)
- GPT-5.1-Codex: —

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| LiveBench Instruction Following | 58.1% | — |
| LMArena Instruction Following | 1206 | — |

## Long Context

- Gemma 2 27B: 37.3 (#218)
- GPT-5.1-Codex: —

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| LMArena Longer Query | 1231 | — |

## Writing & Preference

- Gemma 2 27B: 44.2 (#225)
- GPT-5.1-Codex: —

| Benchmark | Gemma 2 27B | GPT-5.1-Codex |
|---|---|---|
| LMArena Text | 1231 | — |
| LMArena Creative Writing | 1241 | — |
| LMArena Multi-Turn | 1224 | — |
| LiveBench Language | 32.6% | — |

## FAQ

### Is Gemma 2 27B better than GPT-5.1-Codex?

GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 29.4 on the Noometry Index. Gemma 2 27B costs 5.3× 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 2 27B or GPT-5.1-Codex?

Gemma 2 27B is cheaper. It lists at $0.65 per million input tokens and $0.65 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

### Is Gemma 2 27B or GPT-5.1-Codex better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 34.1 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 8K.

### How many benchmarks do Gemma 2 27B and GPT-5.1-Codex share?

0 benchmarks have published results for both models. Gemma 2 27B has 34 scored results on Noometry and GPT-5.1-Codex has 6.