# GPT-5.5 Instant vs Grok-2 (Dec 2024)

> GPT-5.5 Instant is the stronger model overall, scoring 42.5 to 33.4 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-5-instant-vs-grok-2
- Last updated: 2026-10-10
- Shared benchmarks: 20

## Summary

- They share 20 benchmarks with published results for both. GPT-5.5 Instant scores higher in 8 categories and Grok-2 (Dec 2024) in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where GPT-5.5 Instant leads 48.9 to 29.8.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 68.1% for GPT-5.5 Instant and 11.5% for Grok-2 (Dec 2024).

## Snapshot

| | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 42.5 | 33.4 |
| Rank | 99 | 233 |
| Context | — | — |
| Input $/M | — | — |
| Output $/M | — | — |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.5 Instant: 43.7 (#73)
- Grok-2 (Dec 2024): 32.9 (#254)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Coding | 1433 | 1288 |
| SciCode | 48.6% | — |
| WeirdML | — | 22.2% |
| LiveBench Coding | — | 46.4% |

## Reasoning

- GPT-5.5 Instant: 24.2 (#149)
- Grok-2 (Dec 2024): 16.4 (#294)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Hard Prompts | 1426 | 1272 |
| Epoch Capabilities Index | 142.48 | 130.48 |
| SimpleBench | — | 22.7% |
| CritPt | 0% | — |
| Chess Puzzles | 12% | — |
| LiveBench Reasoning | — | 54.8% |
| DTBench | — | 65.2% |
| LiveBench Data Analysis | — | 54.5% |
| LiveBench | — | 54.3% |

## Math

- GPT-5.5 Instant: 26.1 (#241)
- Grok-2 (Dec 2024): 19.6 (#278)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 68.1% | 11.5% |
| LMArena Math | 1420 | 1283 |
| FrontierMath (Tiers 1-3) | 26.3% | — |
| FrontierMath Tier 4 | 2.4% | — |
| LiveBench Math | — | 54.9% |
| MATH Level 5 | — | 63.5% |
| FrontierMath (Feb 2025 set) | — | 0.7% |

## Knowledge

- GPT-5.5 Instant: 48.9 (#68)
- Grok-2 (Dec 2024): 29.8 (#225)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| GPQA Diamond | 82.5% | 53.8% |
| LMArena Expert | 1409 | 1254 |
| Confabulations | — | 20.1% |

## Multimodal

- GPT-5.5 Instant: 39.3 (#48)
- Grok-2 (Dec 2024): —

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Vision | 1250 | — |
| LMArena Document | 1403 | — |

## Multilingual

- GPT-5.5 Instant: 53.0 (#76)
- Grok-2 (Dec 2024): 43.3 (#183)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Non-English | 1417 | 1282 |
| LMArena Chinese | 1457 | 1289 |
| LMArena French | 1428 | 1317 |
| LMArena German | 1410 | 1287 |
| LMArena Japanese | 1408 | 1244 |
| LMArena Korean | 1393 | 1237 |
| LMArena Russian | 1430 | 1286 |
| LMArena Spanish | 1430 | 1281 |

## Instruction Following

- GPT-5.5 Instant: 74.4 (#94)
- Grok-2 (Dec 2024): 67.1 (#197)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Instruction Following | 1407 | 1270 |
| LiveBench Instruction Following | — | 69.6% |

## Long Context

- GPT-5.5 Instant: 43.4 (#92)
- Grok-2 (Dec 2024): 38.7 (#186)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Longer Query | 1422 | 1276 |

## Writing & Preference

- GPT-5.5 Instant: 62.0 (#81)
- Grok-2 (Dec 2024): 48.8 (#192)

| Benchmark | GPT-5.5 Instant | Grok-2 (Dec 2024) |
|---|---|---|
| LMArena Text | 1419 | 1305 |
| LMArena Creative Writing | 1420 | 1284 |
| LMArena Multi-Turn | 1434 | 1290 |
| Short-Story Creative Writing | — | 63.6% |
| LiveBench Language | — | 45.6% |

## FAQ

### Is GPT-5.5 Instant better than Grok-2 (Dec 2024)?

GPT-5.5 Instant is the stronger model overall, scoring 42.5 to 33.4 on the Noometry Index.

### Is GPT-5.5 Instant or Grok-2 (Dec 2024) better for coding?

GPT-5.5 Instant scores higher on coding benchmarks: 43.7 versus 32.9 in the Noometry coding category.

### How many benchmarks do GPT-5.5 Instant and Grok-2 (Dec 2024) share?

20 benchmarks have published results for both models. GPT-5.5 Instant has 27 scored results on Noometry and Grok-2 (Dec 2024) has 34.