# GPT-5.5 vs Grok 3

> GPT-5.5 is the stronger model overall, scoring 63.4 to 39.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-5-vs-grok-3
- Last updated: 2026-10-10
- Shared benchmarks: 29

## Summary

- They share 29 benchmarks with published results for both. GPT-5.5 scores higher in 9 categories and Grok 3 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 leads 72.7 to 13.8.
- The biggest single-benchmark swing is ARC-AGI-1: 95% for GPT-5.5 and 5.5% for Grok 3.

## Snapshot

| | GPT-5.5 | Grok 3 |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 63.4 | 39.6 |
| Rank | 8 | 150 |
| Context | 1.05M | — |
| Input $/M | $5 | — |
| Output $/M | $30 | — |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.5: 58.3 (#13)
- Grok 3: 41.5 (#113)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| WeirdML | 84.9% | 37.2% |
| LMArena Coding | 1494 | 1432 |
| SWE-bench Verified | 80.6% | — |
| DeepSWE | 67% | — |
| FrontierCode | 43% | — |
| Aider Polyglot | — | 53.3% |
| LMArena WebDev | 1512 | — |
| SciCode | 56.1% | — |
| GSO | 40.2% | — |
| MirrorCode | 10% | — |
| ALE-Bench | 1,943 | — |

## Agentic & Tool Use

- GPT-5.5: 50.7 (#6)
- Grok 3: 30.2 (#69)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| Terminal-Bench | 84.7% | — |
| APEX-Agents | 55.1% | — |
| OSWorld 2.0 | 13% | — |
| Remote Labor Index | 6.3% | — |
| τ²-bench Banking | 44.6% | — |
| DeepResearch Bench | 54% | — |
| PostTrainBench | 27.2% | — |
| BALROG | — | 29.5% |
| ExploitBench | 47.4% | — |
| GBAEval | 53.2% | — |
| GDP.pdf | 26% | — |
| LMArena Search | 1242 | — |
| Vending-Bench 2 | 7,524 | — |

## Reasoning

- GPT-5.5: 72.7 (#8)
- Grok 3: 13.8 (#322)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| ARC-AGI-2 | 85% | 0% |
| SimpleBench | 69% | 36.1% |
| Kagi LLM Benchmark | 88.8% | 61.3% |
| ARC-AGI-1 | 95% | 5.5% |
| LMArena Hard Prompts | 1489 | 1433 |
| Epoch Capabilities Index | 159.25 | 138.34 |
| NYT Connections (extended) | 96.2% | — |
| CritPt | 27.1% | — |
| Chess Puzzles | 54% | — |
| EBR-Bench | 34.3% | — |
| Mystery Game Puzzles | 56% | — |
| DTBench | 96% | — |
| LMCA | 54.3% | — |
| Surface Evolver Bench | 88.1% | — |
| Bench to the Future 3 | 0.14 | — |
| ForecastBench | 60.6 | — |

## Math

- GPT-5.5: 81.5 (#9)
- Grok 3: 36.2 (#122)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 55.6% |
| LMArena Math | 1486 | 1390 |
| FrontierMath (Feb 2025 set) | 51.7% | 3.8% |
| FrontierMath Tier 4 (v1) | 35.4% | 0% |
| FrontierMath (Tiers 1-3) | 85.3% | — |
| FrontierMath Tier 4 | 72.5% | — |
| MathArena Final-Answer Competitions | 94.3% | — |
| ProofBench | 50% | — |
| Omni-MATH | — | 46.4% |
| MATH Level 5 | — | 88.7% |
| FrontierMath Erdős | 0% | — |

## Knowledge

- GPT-5.5: 64.4 (#14)
- Grok 3: 46.0 (#76)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| GPQA Diamond | 94% | 75.8% |
| Vectara Hallucination Rate | 9.3% | 5.8% |
| LMArena Expert | 1508 | 1420 |
| SimpleQA Verified | 63% | — |
| MMLU-Pro | — | 78.8% |
| Confabulations | — | 14.2% |
| GPQA (HELM) | — | 65% |

## Multimodal

- GPT-5.5: 47.1 (#11)
- Grok 3: —

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| LMArena Vision | 1297 | — |
| Blueprint-Bench 2 | 36.2% | — |
| Furniture Assembly | 44.2% | — |
| LMArena Document | 1486 | — |

## Multilingual

- GPT-5.5: 56.5 (#19)
- Grok 3: 52.5 (#81)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| LMArena Non-English | 1467 | 1411 |
| LMArena Chinese | 1535 | 1448 |
| LMArena French | 1486 | 1460 |
| LMArena German | 1478 | 1431 |
| LMArena Japanese | 1498 | 1389 |
| LMArena Korean | 1461 | 1374 |
| LMArena Russian | 1473 | 1416 |
| LMArena Spanish | 1469 | 1417 |

## Instruction Following

- GPT-5.5: 77.7 (#18)
- Grok 3: 75.2 (#69)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| LMArena Instruction Following | 1479 | 1409 |
| IFEval | — | 88.4% |

## Long Context

- GPT-5.5: 48.3 (#12)
- Grok 3: 38.7 (#187)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| LMArena Longer Query | 1484 | 1439 |
| Fiction.LiveBench | — | 58.3% |
| CL-bench Life | 22.2% | — |

## Writing & Preference

- GPT-5.5: 72.8 (#13)
- Grok 3: 56.0 (#136)

| Benchmark | GPT-5.5 | Grok 3 |
|---|---|---|
| LMArena Text | 1471 | 1426 |
| LMArena Creative Writing | 1455 | 1414 |
| EQ-Bench Creative Writing | 1844 | 1186 |
| LMArena Multi-Turn | 1477 | 1424 |
| Short-Story Creative Writing | — | 76.4% |
| WildBench | — | 84.9% |
| EQ-Bench 4 | 1315 | — |

## FAQ

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

GPT-5.5 is the stronger model overall, scoring 63.4 to 39.6 on the Noometry Index.

### Is GPT-5.5 or Grok 3 better for coding?

GPT-5.5 scores higher on coding benchmarks: 58.3 versus 41.5 in the Noometry coding category.

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

29 benchmarks have published results for both models. GPT-5.5 has 71 scored results on Noometry and Grok 3 has 40.