# Claude Opus 5.5 vs Grok 4

> Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 48.1 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-opus-5-5-vs-grok-4
- Last updated: 2026-10-12
- Shared benchmarks: 20

## Summary

- They share 20 benchmarks with published results for both. Claude Opus 5.5 scores higher in 9 categories and Grok 4 in 1 category; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 5.5 leads 80.2 to 36.7.
- The biggest single-benchmark swing is ARC-AGI-2: 93.3% for Claude Opus 5.5 and 16% for Grok 4.

## Snapshot

| | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 68.6 | 48.1 |
| Rank | 3 | 56 |
| Context | 1M | — |
| Input $/M | $4 | — |
| Output $/M | $20 | — |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 5.5: 71.9 (#3)
- Grok 4: 50.3 (#46)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| LMArena Coding | 1547 | 1408 |
| FrontierCode | 54.6% | — |
| Aider Polyglot | — | 79.6% |
| CursorBench | 57.8% | — |
| LMArena WebDev | 1813 | — |
| FrontierSWE | 62.3% | — |
| SciCode | 66.9% | — |
| WeirdML | — | 45.7% |
| MirrorCode | 77.4% | — |
| ALE-Bench | 2,147 | — |

## Agentic & Tool Use

- Claude Opus 5.5: 45.3 (#15)
- Grok 4: 32.3 (#68)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| Terminal-Bench | — | 27.2% |
| APEX-Agents | 73.5% | — |
| Berkeley Function Calling Leaderboard | — | 63% |
| GDPval | — | 21.1% |
| Cybench | — | 43% |
| DeepResearch Bench | — | 47.3% |
| BALROG | — | 43.6% |
| GDP.pdf | 30.6% | — |
| LMArena Search | — | 1142 |
| METR Time Horizons | — | 66.6% |
| Vending-Bench 2 | 9,235 | — |

## Reasoning

- Claude Opus 5.5: 80.2 (#3)
- Grok 4: 36.7 (#65)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| ARC-AGI-2 | 93.3% | 16% |
| ARC-AGI-1 | 98.5% | 66.7% |
| LMArena Hard Prompts | 1535 | 1409 |
| Epoch Capabilities Index | 167.33 | 146.44 |
| SimpleBench | — | 60.5% |
| Kagi LLM Benchmark | — | 73.6% |
| NYT Connections (extended) | 88.5% | — |
| CritPt | 31.7% | — |
| Chess Puzzles | — | 28% |
| EBR-Bench | 71.4% | — |
| Mystery Game Puzzles | 71% | — |
| DTBench | 98.9% | — |
| LMCA | 68.2% | — |
| ForecastBench | — | 60.9 |

## Math

- Claude Opus 5.5: 91.8 (#3)
- Grok 4: 48.4 (#64)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 84% |
| LMArena Math | 1506 | 1422 |
| FrontierMath (Tiers 1-3) | 91.2% | — |
| FrontierMath Tier 4 | 95% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 60.3% |
| FrontierMath (Feb 2025 set) | — | 19.7% |
| FrontierMath Erdős | 2.9% | — |
| FrontierMath Tier 4 (v1) | — | 2.1% |

## Knowledge

- Claude Opus 5.5: 66.4 (#10)
- Grok 4: 53.8 (#55)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| GPQA Diamond | 90.6% | 87% |
| LMArena Expert | 1547 | 1415 |
| SimpleQA Verified | 72.2% | — |
| MMLU-Pro | — | 85.1% |
| Confabulations | — | 12.4% |
| GPQA (HELM) | — | 72.7% |

## Multimodal

- Claude Opus 5.5: 57.8 (#1)
- Grok 4: 33.7 (#94)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| LMArena Vision | 1321 | 1210 |
| GeoBench | — | 45% |
| Blueprint-Bench 2 | 51.2% | — |
| Furniture Assembly | 83.3% | — |

## Multilingual

- Claude Opus 5.5: 59.1 (#2)
- Grok 4: 51.8 (#103)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| LMArena Non-English | 1507 | 1403 |
| LMArena Chinese | 1588 | 1427 |
| LMArena French | 1514 | 1418 |
| LMArena Russian | 1520 | 1410 |
| LMArena Spanish | 1507 | 1420 |
| LMArena German | — | 1429 |
| LMArena Japanese | — | 1394 |
| LMArena Korean | — | 1377 |

## Instruction Following

- Claude Opus 5.5: 80.0 (#3)
- Grok 4: 79.2 (#5)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| LMArena Instruction Following | 1537 | 1387 |
| IFEval | — | 94.9% |

## Long Context

- Claude Opus 5.5: 47.1 (#19)
- Grok 4: 63.1 (#4)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| LMArena Longer Query | 1532 | 1409 |
| Fiction.LiveBench | — | 94.4% |

## Writing & Preference

- Claude Opus 5.5: 78.2 (#3)
- Grok 4: 58.5 (#116)

| Benchmark | Claude Opus 5.5 | Grok 4 |
|---|---|---|
| LMArena Text | 1515 | 1411 |
| LMArena Creative Writing | 1533 | 1397 |
| LMArena Multi-Turn | 1499 | 1416 |
| Short-Story Creative Writing | — | 76.9% |
| EQ-Bench Creative Writing | 2050 | — |
| WildBench | — | 79.7% |

## FAQ

### Is Claude Opus 5.5 better than Grok 4?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 48.1 on the Noometry Index.

### Is Claude Opus 5.5 or Grok 4 better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 50.3 in the Noometry coding category.

### How many benchmarks do Claude Opus 5.5 and Grok 4 share?

20 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Grok 4 has 48.