# GPT-5.1-Codex vs Llama 2-13B

> GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 29.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-llama-2-13b
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where GPT-5.1-Codex leads 41.9 to 30.9.
- Llama 2-13B has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| Provider | OpenAI | Meta |
| Noometry Index | 38.6 | 29.6 |
| Rank | 186 | 309 |
| Context | 400K | — |
| Input $/M | $1.25 | — |
| Output $/M | $10 | — |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.9 (#116)
- Llama 2-13B: 30.9 (#291)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| SWE-bench Verified (bash only) | 66% | — |
| LMArena WebDev | 1337 | — |
| LMArena Coding | — | 1062 |
| ALE-Bench | 1,245 | — |

## Agentic & Tool Use

- GPT-5.1-Codex: 38.0 (#33)
- Llama 2-13B: —

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- Llama 2-13B: 12.8 (#337)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| Chess Puzzles | — | 0% |
| LMArena Hard Prompts | — | 1051 |
| DTBench | — | 42.2% |
| BIG-Bench Hard | — | 58.2% |
| Epoch Capabilities Index | — | 106.17 |
| HellaSwag | — | 80.7% |
| LAMBADA | — | 76.5% |
| PIQA | — | 80.8% |
| WinoGrande | — | 72.8% |

## Math

- GPT-5.1-Codex: 30.3 (#235)
- Llama 2-13B: 31.1 (#229)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| ProofBench | 9% | — |
| LMArena Math | — | 1065 |
| GSM8K | — | 36.9% |

## Knowledge

- GPT-5.1-Codex: —
- Llama 2-13B: 28.1 (#249)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| LMArena Expert | — | 1030 |
| ARC (AI2) Challenge | — | 60.3% |
| BoolQ | — | 82.4% |
| MMLU | — | 55.6% |
| OpenBookQA | — | 57% |
| TriviaQA | — | 79.6% |

## Multimodal

- GPT-5.1-Codex: —
- Llama 2-13B: —

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| ScienceQA | — | 55.8% |

## Multilingual

- GPT-5.1-Codex: —
- Llama 2-13B: 26.5 (#279)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| LMArena Non-English | — | 1024 |
| LMArena Chinese | — | 1001 |
| LMArena French | — | 1044 |
| LMArena German | — | 1009 |
| LMArena Japanese | — | 894 |
| LMArena Korean | — | 953 |
| LMArena Russian | — | 1055 |
| LMArena Spanish | — | 1087 |

## Instruction Following

- GPT-5.1-Codex: —
- Llama 2-13B: 53.3 (#287)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| LMArena Instruction Following | — | 1045 |

## Long Context

- GPT-5.1-Codex: —
- Llama 2-13B: 32.3 (#269)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| LMArena Longer Query | — | 1064 |

## Writing & Preference

- GPT-5.1-Codex: —
- Llama 2-13B: 29.8 (#289)

| Benchmark | GPT-5.1-Codex | Llama 2-13B |
|---|---|---|
| LMArena Text | — | 1084 |
| LMArena Creative Writing | — | 1047 |
| LMArena Multi-Turn | — | 1050 |

## FAQ

### Is GPT-5.1-Codex better than Llama 2-13B?

GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 29.6 on the Noometry Index.

### Is GPT-5.1-Codex or Llama 2-13B better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 30.9 in the Noometry coding category.

### How many benchmarks do GPT-5.1-Codex and Llama 2-13B share?

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Llama 2-13B has 32.