# GPT-5.1-Codex vs Grok-2 (Dec 2024)

> GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 33.4 on the Noometry Index.

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

## Summary

- The widest gap is in math, where GPT-5.1-Codex leads 29.3 to 19.6.

## Snapshot

| | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 38.2 | 33.4 |
| Rank | 178 | 233 |
| Context | 400K | — |
| Input $/M | $1.25 | — |
| Output $/M | $10 | — |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.1-Codex: 41.7 (#107)
- Grok-2 (Dec 2024): 32.9 (#254)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| SWE-bench Verified (bash only) | 66% | — |
| LMArena WebDev | 1337 | — |
| WeirdML | — | 22.2% |
| LiveBench Coding | — | 46.4% |
| LMArena Coding | — | 1288 |
| ALE-Bench | 1,245 | — |

## Agentic & Tool Use

- GPT-5.1-Codex: 37.8 (#32)
- Grok-2 (Dec 2024): —

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- Grok-2 (Dec 2024): 16.4 (#294)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| SimpleBench | — | 22.7% |
| LiveBench Reasoning | — | 54.8% |
| LMArena Hard Prompts | — | 1272 |
| DTBench | — | 65.2% |
| LiveBench Data Analysis | — | 54.5% |
| Epoch Capabilities Index | — | 130.48 |
| LiveBench | — | 54.3% |

## Math

- GPT-5.1-Codex: 29.3 (#218)
- Grok-2 (Dec 2024): 19.6 (#278)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 11.5% |
| ProofBench | 9% | — |
| LiveBench Math | — | 54.9% |
| LMArena Math | — | 1283 |
| MATH Level 5 | — | 63.5% |
| FrontierMath (Feb 2025 set) | — | 0.7% |

## Knowledge

- GPT-5.1-Codex: —
- Grok-2 (Dec 2024): 29.8 (#225)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| GPQA Diamond | — | 53.8% |
| Confabulations | — | 20.1% |
| LMArena Expert | — | 1254 |

## Multilingual

- GPT-5.1-Codex: —
- Grok-2 (Dec 2024): 43.3 (#183)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Non-English | — | 1282 |
| LMArena Chinese | — | 1289 |
| LMArena French | — | 1317 |
| LMArena German | — | 1287 |
| LMArena Japanese | — | 1244 |
| LMArena Korean | — | 1237 |
| LMArena Russian | — | 1286 |
| LMArena Spanish | — | 1281 |

## Instruction Following

- GPT-5.1-Codex: —
- Grok-2 (Dec 2024): 67.1 (#197)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| LiveBench Instruction Following | — | 69.6% |
| LMArena Instruction Following | — | 1270 |

## Long Context

- GPT-5.1-Codex: —
- Grok-2 (Dec 2024): 38.7 (#186)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Longer Query | — | 1276 |

## Writing & Preference

- GPT-5.1-Codex: —
- Grok-2 (Dec 2024): 48.8 (#192)

| Benchmark | GPT-5.1-Codex | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Text | — | 1305 |
| LMArena Creative Writing | — | 1284 |
| Short-Story Creative Writing | — | 63.6% |
| LMArena Multi-Turn | — | 1290 |
| LiveBench Language | — | 45.6% |

## FAQ

### Is GPT-5.1-Codex better than Grok-2 (Dec 2024)?

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 33.4 on the Noometry Index.

### Is GPT-5.1-Codex or Grok-2 (Dec 2024) better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.7 versus 32.9 in the Noometry coding category.

### How many benchmarks do GPT-5.1-Codex and Grok-2 (Dec 2024) share?

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Grok-2 (Dec 2024) has 34.