# Claude Opus 4.5 vs Grok 4.1 Fast

> Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 36× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-opus-4-5-vs-grok-4-1-fast
- Last updated: 2026-10-10
- Shared benchmarks: 30

## Summary

- They share 30 benchmarks with published results for both. Claude Opus 4.5 scores higher in 8 categories and Grok 4.1 Fast in 2 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Claude Opus 4.5 leads 56.5 to 33.1.
- The biggest single-benchmark swing is NYT Connections (extended): 52.5% for Claude Opus 4.5 and 87.4% for Grok 4.1 Fast.
- Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
- Claude Opus 4.5 accepts more context: 200K tokens versus 128K.

## Snapshot

| | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 50.5 | 41.4 |
| Rank | 47 | 136 |
| Context | 200K | 128K |
| Input $/M | $5 | $0.20 |
| Output $/M | $25 | $0.50 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 4.5: 54.8 (#27)
- Grok 4.1 Fast: 34.1 (#245)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena WebDev | 1494 | 1242 |
| LMArena Coding | 1504 | 1411 |
| ALE-Bench | 1,025 | 394.93 |
| SWE-bench Verified | 76.7% | — |
| SWE-bench Verified (bash only) | 76.8% | — |
| SWE-bench Multilingual | 70.7% | — |
| GSO | 26.5% | — |
| WeirdML | 63.7% | — |
| AlgoTune | 1.77 | — |

## Agentic & Tool Use

- Claude Opus 4.5: 47.3 (#12)
- Grok 4.1 Fast: 36.3 (#39)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | 77.5% | 69.6% |
| τ²-bench Banking | 24.7% | 13.1% |
| LMArena Search | 1180 | 1171 |
| Vending-Bench 2 | 4,967 | 1,107 |
| Terminal-Bench | 63.1% | — |
| GDPval | 45.5% | — |
| Remote Labor Index | 3.8% | — |
| τ²-bench Airline | 84% | — |
| τ²-bench Retail | 79.6% | — |
| τ²-bench Telecom | 92.3% | — |
| Cybench | 82% | — |
| DeepResearch Bench | 54.8% | — |
| OSWorld | 66.3% | — |
| BALROG | 43.5% | — |
| METR Time Horizons | 75% | — |

## Reasoning

- Claude Opus 4.5: 42.6 (#51)
- Grok 4.1 Fast: 43.4 (#49)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| SimpleBench | 62% | 56% |
| NYT Connections (extended) | 52.5% | 87.4% |
| LMArena Hard Prompts | 1476 | 1407 |
| DTBench | 89.9% | 87.7% |
| ForecastBench | 60.7 | 61 |
| ARC-AGI-2 | 37.6% | — |
| Kagi LLM Benchmark | 80.2% | — |
| ARC-AGI-1 | 80% | — |
| Chess Puzzles | 12% | — |
| EnigmaEval | 11.9% | — |
| EBR-Bench | 14.3% | — |
| Mystery Game Puzzles | 22% | — |
| LMCA | 44.5% | — |
| Epoch Capabilities Index | 150.09 | — |

## Math

- Claude Opus 4.5: 38.6 (#132)
- Grok 4.1 Fast: 31.9 (#221)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| ProofBench | 36% | 4% |
| LMArena Math | 1463 | 1408 |
| FrontierMath (Tiers 1-3) | 34.4% | — |
| FrontierMath Tier 4 | 4.9% | — |
| MathArena Final-Answer Competitions | — | 60.9% |
| OTIS Mock AIME 2024-2025 | 86.1% | — |
| FrontierMath (Feb 2025 set) | 20.7% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Claude Opus 4.5: 56.5 (#44)
- Grok 4.1 Fast: 33.1 (#207)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| Vectara Hallucination Rate | 10.9% | 17.8% |
| LMArena Expert | 1487 | 1399 |
| GPQA Diamond | 86% | — |
| Humanity's Last Exam | 25.2% | — |
| SimpleQA Verified | 45.7% | — |

## Multimodal

- Claude Opus 4.5: 31.4 (#107)
- Grok 4.1 Fast: 37.0 (#76)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |
| GeoBench | 75% | — |
| VPCT | 40% | — |
| Furniture Assembly | 28.3% | — |
| LMArena Document | 1462 | — |

## Multilingual

- Claude Opus 4.5: 54.3 (#47)
- Grok 4.1 Fast: 51.0 (#114)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | 1438 | 1391 |
| LMArena Chinese | 1470 | 1441 |
| LMArena French | 1471 | 1415 |
| LMArena German | 1449 | 1404 |
| LMArena Japanese | 1416 | 1349 |
| LMArena Korean | 1424 | 1361 |
| LMArena Russian | 1447 | 1387 |
| LMArena Spanish | 1458 | 1413 |

## Instruction Following

- Claude Opus 4.5: 77.5 (#19)
- Grok 4.1 Fast: 72.7 (#133)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | 1478 | 1376 |

## Long Context

- Claude Opus 4.5: 46.5 (#22)
- Grok 4.1 Fast: 42.4 (#126)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | 1480 | 1390 |
| CL-bench | 21.1% | — |

## Writing & Preference

- Claude Opus 4.5: 68.1 (#28)
- Grok 4.1 Fast: 57.2 (#131)

| Benchmark | Claude Opus 4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | 1451 | 1408 |
| LMArena Creative Writing | 1445 | 1394 |
| EQ-Bench Creative Writing | 1687 | 1327 |
| LMArena Multi-Turn | 1466 | 1389 |

## FAQ

### Is Claude Opus 4.5 better than Grok 4.1 Fast?

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 36× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

### Which is cheaper, Claude Opus 4.5 or Grok 4.1 Fast?

Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

### Is Claude Opus 4.5 or Grok 4.1 Fast better for coding?

Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 34.1 in the Noometry coding category.

### Which has the bigger context window?

Claude Opus 4.5 does, with 200K tokens against 128K.

### How many benchmarks do Claude Opus 4.5 and Grok 4.1 Fast share?

30 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Grok 4.1 Fast has 32.