# GPT-5.1-Codex vs Granite 4.2 8B

> Granite 4.2 8B is the stronger model overall, scoring 40.0 to 38.2 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-granite-4-2-8b
- Last updated: 2026-10-10
- Shared benchmarks: 0

## Summary

- Granite 4.2 8B is cheaper at $0.06 / $0.25 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.
- Granite 4.2 8B has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| Provider | OpenAI | IBM |
| Noometry Index | 38.2 | 40.0 |
| Rank | 178 | 143 |
| Context | 400K | 131K |
| Input $/M | $1.25 | $0.06 |
| Output $/M | $10 | $0.25 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.7 (#107)
- Granite 4.2 8B: 39.9 (#138)

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| SWE-bench Verified (bash only) | 66% | — |
| LMArena WebDev | 1337 | — |
| LMArena Coding | — | 1379 |
| ALE-Bench | 1,245 | — |

## Agentic & Tool Use

- GPT-5.1-Codex: 37.8 (#32)
- Granite 4.2 8B: —

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- Granite 4.2 8B: 25.5 (#130)

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| LMArena Hard Prompts | — | 1327 |

## Math

- GPT-5.1-Codex: 29.3 (#218)
- Granite 4.2 8B: —

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| ProofBench | 9% | — |

## Knowledge

- GPT-5.1-Codex: —
- Granite 4.2 8B: 37.7 (#144)

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| LMArena Expert | — | 1380 |

## Multilingual

- GPT-5.1-Codex: —
- Granite 4.2 8B: 44.5 (#173)

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| LMArena Non-English | — | 1299 |
| LMArena Chinese | — | 1361 |
| LMArena Russian | — | 1283 |

## Instruction Following

- GPT-5.1-Codex: —
- Granite 4.2 8B: 68.7 (#183)

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| LMArena Instruction Following | — | 1298 |

## Long Context

- GPT-5.1-Codex: —
- Granite 4.2 8B: 40.2 (#154)

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| LMArena Longer Query | — | 1323 |

## Writing & Preference

- GPT-5.1-Codex: —
- Granite 4.2 8B: 49.8 (#183)

| Benchmark | GPT-5.1-Codex | Granite 4.2 8B |
|---|---|---|
| LMArena Text | — | 1319 |
| LMArena Creative Writing | — | 1238 |
| LMArena Multi-Turn | — | 1299 |

## FAQ

### Is GPT-5.1-Codex better than Granite 4.2 8B?

Granite 4.2 8B is the stronger model overall, scoring 40.0 to 38.2 on the Noometry Index.

### Which is cheaper, GPT-5.1-Codex or Granite 4.2 8B?

Granite 4.2 8B is cheaper. It lists at $0.06 per million input tokens and $0.25 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

### Is GPT-5.1-Codex or Granite 4.2 8B better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.7 versus 39.9 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 GPT-5.1-Codex and Granite 4.2 8B share?

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Granite 4.2 8B has 11.