# Claude Opus 5.5 vs Grok-3 mini

> Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 41.0 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-opus-5-5-vs-grok-3-mini
- Last updated: 2026-10-10
- Shared benchmarks: 15

## Summary

- They share 15 benchmarks with published results for both. Claude Opus 5.5 scores higher in 8 categories and Grok-3 mini in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 5.5 leads 79.5 to 13.8.
- The biggest single-benchmark swing is ARC-AGI-2: 92.5% for Claude Opus 5.5 and 0.4% for Grok-3 mini.

## Snapshot

| | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 68.5 | 41.0 |
| Rank | 3 | 130 |
| Context | 1M | — |
| Input $/M | $4 | — |
| Output $/M | $20 | — |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 5.5: 71.4 (#1)
- Grok-3 mini: 40.4 (#126)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| LMArena Coding | 1545 | 1380 |
| FrontierCode | 54.4% | — |
| Aider Polyglot | — | 49.3% |
| CursorBench | 57.8% | — |
| LMArena WebDev | 1820 | — |
| FrontierSWE | 62.3% | — |
| SciCode | 66.9% | — |
| WeirdML | — | 42.6% |
| MirrorCode | 77.4% | — |

## Agentic & Tool Use

- Claude Opus 5.5: 45.3 (#13)
- Grok-3 mini: —

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| APEX-Agents | 73.5% | — |
| GDP.pdf | 30.6% | — |

## Reasoning

- Claude Opus 5.5: 79.5 (#2)
- Grok-3 mini: 13.8 (#323)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| ARC-AGI-2 | 92.5% | 0.4% |
| ARC-AGI-1 | 97.5% | 16.5% |
| LMArena Hard Prompts | 1545 | 1374 |
| Kagi LLM Benchmark | — | 61.3% |
| NYT Connections (extended) | 88.5% | — |
| CritPt | 31.7% | — |
| EBR-Bench | 71.4% | — |
| Mystery Game Puzzles | 71% | — |
| DTBench | 98.9% | — |
| LMCA | 68.2% | — |
| Epoch Capabilities Index | — | 140.35 |

## Math

- Claude Opus 5.5: 92.4 (#2)
- Grok-3 mini: 40.3 (#78)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 77.8% |
| FrontierMath (Tiers 1-3) | 91.2% | — |
| FrontierMath Tier 4 | 95% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 31.8% |
| LMArena Math | — | 1386 |
| MATH Level 5 | — | 90.9% |
| FrontierMath (Feb 2025 set) | — | 5.9% |

## Knowledge

- Claude Opus 5.5: 66.6 (#9)
- Grok-3 mini: 46.3 (#75)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| GPQA Diamond | 90.6% | 76.3% |
| LMArena Expert | 1564 | 1395 |
| SimpleQA Verified | 72.2% | — |
| MMLU-Pro | — | 79.9% |
| Confabulations | — | 10.8% |
| GPQA (HELM) | — | 67.5% |

## Multimodal

- Claude Opus 5.5: 56.5 (#2)
- Grok-3 mini: —

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| Furniture Assembly | 83.3% | — |

## Multilingual

- Claude Opus 5.5: 59.8 (#1)
- Grok-3 mini: 48.3 (#141)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| LMArena Non-English | 1513 | 1352 |
| LMArena Chinese | 1572 | 1387 |
| LMArena Russian | 1532 | 1352 |
| LMArena French | — | 1357 |
| LMArena German | — | 1350 |
| LMArena Japanese | — | 1343 |
| LMArena Korean | — | 1336 |
| LMArena Spanish | — | 1379 |

## Instruction Following

- Claude Opus 5.5: 80.1 (#2)
- Grok-3 mini: 78.7 (#8)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| LMArena Instruction Following | 1535 | 1356 |
| IFEval | — | 95.1% |

## Long Context

- Claude Opus 5.5: 47.3 (#18)
- Grok-3 mini: 41.0 (#142)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| LMArena Longer Query | 1540 | 1372 |
| Fiction.LiveBench | — | 66.7% |

## Writing & Preference

- Claude Opus 5.5: 78.7 (#3)
- Grok-3 mini: 52.7 (#163)

| Benchmark | Claude Opus 5.5 | Grok-3 mini |
|---|---|---|
| LMArena Text | 1518 | 1370 |
| LMArena Creative Writing | 1538 | 1342 |
| LMArena Multi-Turn | 1520 | 1355 |
| Short-Story Creative Writing | — | 73.5% |
| EQ-Bench Creative Writing | 2050 | — |
| WildBench | — | 65.1% |

## FAQ

### Is Claude Opus 5.5 better than Grok-3 mini?

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 41.0 on the Noometry Index.

### Is Claude Opus 5.5 or Grok-3 mini better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.4 versus 40.4 in the Noometry coding category.

### How many benchmarks do Claude Opus 5.5 and Grok-3 mini share?

15 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and Grok-3 mini has 35.