# GPT-5.5 Pro vs Grok 3

> GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 39.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-5-pro-vs-grok-3
- Last updated: 2026-10-10
- Shared benchmarks: 8

## Summary

- They share 8 benchmarks with published results for both. GPT-5.5 Pro scores higher in 3 categories and Grok 3 in 0 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 Pro leads 73.3 to 13.7.
- The biggest single-benchmark swing is ARC-AGI-1: 96.5% for GPT-5.5 Pro and 5.5% for Grok 3.

## Snapshot

| | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 64.3 | 39.9 |
| Rank | 8 | 157 |
| Context | 1.05M | — |
| Input $/M | $30 | — |
| Output $/M | $180 | — |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.5 Pro: —
- Grok 3: 41.9 (#115)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| Aider Polyglot | — | 53.3% |
| WeirdML | — | 37.2% |
| LMArena Coding | — | 1432 |

## Agentic & Tool Use

- GPT-5.5 Pro: —
- Grok 3: 30.5 (#76)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| BALROG | — | 29.5% |

## Reasoning

- GPT-5.5 Pro: 73.3 (#10)
- Grok 3: 13.7 (#333)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| ARC-AGI-2 | 84.6% | 0% |
| SimpleBench | 76.9% | 36.1% |
| ARC-AGI-1 | 96.5% | 5.5% |
| Epoch Capabilities Index | 162.07 | 138.33 |
| Kagi LLM Benchmark | — | 61.3% |
| CritPt | 30.6% | — |
| Chess Puzzles | 64% | — |
| LMArena Hard Prompts | — | 1434 |
| DTBench | 96% | — |
| LMCA | 53.9% | — |

## Math

- GPT-5.5 Pro: 84.0 (#10)
- Grok 3: 38.0 (#145)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 55.6% |
| FrontierMath (Feb 2025 set) | 52.4% | 3.8% |
| FrontierMath Tier 4 (v1) | 39.6% | 0% |
| FrontierMath (Tiers 1-3) | 87.7% | — |
| FrontierMath Tier 4 | 78% | — |
| Omni-MATH | — | 46.4% |
| LMArena Math | — | 1391 |
| MATH Level 5 | — | 88.7% |

## Knowledge

- GPT-5.5 Pro: 64.1 (#19)
- Grok 3: 46.2 (#82)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| GPQA Diamond | 93.9% | 75.8% |
| MMLU-Pro | — | 78.8% |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 5.8% |
| GPQA (HELM) | — | 65% |
| LMArena Expert | — | 1421 |

## Multilingual

- GPT-5.5 Pro: —
- Grok 3: 52.3 (#87)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| LMArena Non-English | — | 1410 |
| LMArena Chinese | — | 1448 |
| LMArena French | — | 1460 |
| LMArena German | — | 1431 |
| LMArena Japanese | — | 1387 |
| LMArena Korean | — | 1373 |
| LMArena Russian | — | 1416 |
| LMArena Spanish | — | 1417 |

## Instruction Following

- GPT-5.5 Pro: —
- Grok 3: 75.0 (#73)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| IFEval | — | 88.4% |
| LMArena Instruction Following | — | 1409 |

## Long Context

- GPT-5.5 Pro: —
- Grok 3: 38.7 (#192)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| Fiction.LiveBench | — | 58.3% |
| LMArena Longer Query | — | 1439 |

## Writing & Preference

- GPT-5.5 Pro: —
- Grok 3: 55.8 (#141)

| Benchmark | GPT-5.5 Pro | Grok 3 |
|---|---|---|
| LMArena Text | — | 1426 |
| LMArena Creative Writing | — | 1414 |
| Short-Story Creative Writing | — | 76.4% |
| EQ-Bench Creative Writing | — | 1186 |
| WildBench | — | 84.9% |
| LMArena Multi-Turn | — | 1425 |

## FAQ

### Is GPT-5.5 Pro better than Grok 3?

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 39.9 on the Noometry Index.

### How many benchmarks do GPT-5.5 Pro and Grok 3 share?

8 benchmarks have published results for both models. GPT-5.5 Pro has 14 scored results on Noometry and Grok 3 has 40.