# Claude Opus 4 vs Grok 4 Fast

> Claude Opus 4 is the stronger model overall, scoring 43.1 to 39.4 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-opus-4-vs-grok-4-fast
- Last updated: 2026-10-10
- Shared benchmarks: 28

## Summary

- They share 28 benchmarks with published results for both. Claude Opus 4 scores higher in 7 categories and Grok 4 Fast in 2 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in long context, where Grok 4 Fast leads 63.2 to 39.6.
- The biggest single-benchmark swing is Fiction.LiveBench: 61.1% for Claude Opus 4 and 94.4% for Grok 4 Fast.

## Snapshot

| | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 43.1 | 39.4 |
| Rank | 100 | 167 |
| Context | 200K | — |
| Input $/M | $15 | — |
| Output $/M | $75 | — |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 4: 47.2 (#62)
- Grok 4 Fast: 32.5 (#271)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| WeirdML | 43.7% | 42.9% |
| LMArena Coding | 1442 | 1429 |
| SWE-bench Verified | 70.7% | — |
| SWE-bench Verified (bash only) | 67.6% | — |
| Aider Polyglot | 72% | — |
| LMArena WebDev | — | 1159 |
| GSO | 6.9% | — |
| AlgoTune | 1.33 | — |

## Agentic & Tool Use

- Claude Opus 4: 34.8 (#42)
- Grok 4 Fast: 29.5 (#86)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| Cybench | 38% | 30% |
| LMArena Search | 1127 | 1171 |
| τ²-bench Banking | — | 15.7% |
| DeepResearch Bench | 46.8% | — |
| METR Time Horizons | 63.9% | — |

## Reasoning

- Claude Opus 4: 27.3 (#121)
- Grok 4 Fast: 22.2 (#201)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| ARC-AGI-2 | 8.6% | 5.3% |
| Kagi LLM Benchmark | 74.3% | 66.1% |
| ARC-AGI-1 | 35.7% | 48.5% |
| LMArena Hard Prompts | 1399 | 1412 |
| DTBench | 81.6% | 82.7% |
| Epoch Capabilities Index | 142.67 | 144.2 |
| ForecastBench | 61.1 | 60.5 |
| SimpleBench | 58.8% | — |
| CritPt | 0.3% | — |
| EnigmaEval | 5.6% | — |
| LMCA | 37.4% | — |

## Math

- Claude Opus 4: 42.0 (#86)
- Grok 4 Fast: 38.9 (#123)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| LMArena Math | 1390 | 1419 |
| OTIS Mock AIME 2024-2025 | 64.4% | — |
| Omni-MATH | 61.6% | — |
| MATH Level 5 | 85% | — |
| FrontierMath (Feb 2025 set) | 4.5% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Claude Opus 4: 44.0 (#88)
- Grok 4 Fast: 32.0 (#214)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| Vectara Hallucination Rate | 12% | 19.7% |
| LMArena Expert | 1386 | 1411 |
| GPQA Diamond | 76.3% | — |
| Humanity's Last Exam | 10.7% | — |
| MMLU-Pro | 87.5% | — |
| Confabulations | 15.9% | — |
| GPQA (HELM) | 70.8% | — |

## Multimodal

- Claude Opus 4: 31.5 (#106)
- Grok 4 Fast: —

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| LMArena Vision | 1192 | — |
| GeoBench | 49% | — |
| VPCT | 38% | — |

## Multilingual

- Claude Opus 4: 48.8 (#138)
- Grok 4 Fast: 51.3 (#111)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| LMArena Non-English | 1362 | 1396 |
| LMArena Chinese | 1386 | 1457 |
| LMArena French | 1372 | 1431 |
| LMArena German | 1391 | 1383 |
| LMArena Japanese | 1331 | 1352 |
| LMArena Korean | 1321 | 1357 |
| LMArena Russian | 1392 | 1389 |
| LMArena Spanish | 1389 | 1415 |

## Instruction Following

- Claude Opus 4: 77.1 (#28)
- Grok 4 Fast: 73.2 (#121)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| LMArena Instruction Following | 1406 | 1387 |
| IFEval | 91.8% | — |

## Long Context

- Claude Opus 4: 39.6 (#172)
- Grok 4 Fast: 63.2 (#3)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| Fiction.LiveBench | 61.1% | 94.4% |
| LMArena Longer Query | 1422 | 1415 |

## Writing & Preference

- Claude Opus 4: 61.2 (#89)
- Grok 4 Fast: 60.0 (#102)

| Benchmark | Claude Opus 4 | Grok 4 Fast |
|---|---|---|
| LMArena Text | 1377 | 1407 |
| LMArena Creative Writing | 1387 | 1387 |
| LMArena Multi-Turn | 1396 | 1414 |
| Short-Story Creative Writing | 83.6% | — |
| EQ-Bench Creative Writing | 1580 | — |
| WildBench | 85.2% | — |

## FAQ

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

Claude Opus 4 is the stronger model overall, scoring 43.1 to 39.4 on the Noometry Index.

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

Claude Opus 4 scores higher on coding benchmarks: 47.2 versus 32.5 in the Noometry coding category.

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

28 benchmarks have published results for both models. Claude Opus 4 has 56 scored results on Noometry and Grok 4 Fast has 30.