# Claude Sonnet 4.5 vs Muse Spark 1.2

> Muse Spark 1.2 is the stronger model overall, scoring 50.3 to 44.1 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-sonnet-4-5-vs-muse-spark-1-2
- Last updated: 2026-10-12
- Shared benchmarks: 26

## Summary

- They share 26 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 2 categories and Muse Spark 1.2 in 8 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Muse Spark 1.2 leads 51.3 to 26.9.
- The biggest single-benchmark swing is NYT Connections (extended): 37.3% for Claude Sonnet 4.5 and 79.2% for Muse Spark 1.2.
- Muse Spark 1.2 is cheaper at $1.25 / $4.25 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.5.
- Muse Spark 1.2 accepts more context: 1.05M tokens versus 200K.

## Snapshot

| | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| Provider | Anthropic | Meta |
| Noometry Index | 44.1 | 50.3 |
| Rank | 81 | 48 |
| Context | 200K | 1.05M |
| Input $/M | $3 | $1.25 |
| Output $/M | $15 | $4.25 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Sonnet 4.5: 47.3 (#61)
- Muse Spark 1.2: 49.2 (#51)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| LMArena WebDev | 1393 | 1533 |
| SciCode | 44.7% | 56.4% |
| WeirdML | 47.7% | 60.3% |
| LMArena Coding | 1489 | 1495 |
| SWE-bench Verified | 71.3% | — |
| DeepSWE | — | 54.9% |
| SWE-bench Verified (bash only) | 71.4% | — |
| SWE-bench Multilingual | 67% | — |
| FrontierSWE | — | 12% |
| GSO | 14.7% | — |
| ALE-Bench | 796.15 | — |
| AlgoTune | 1.52 | — |

## Agentic & Tool Use

- Claude Sonnet 4.5: 38.3 (#32)
- Muse Spark 1.2: 29.4 (#87)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| Terminal-Bench | 46.5% | — |
| APEX-Agents | — | 36.4% |
| Berkeley Function Calling Leaderboard | 73.2% | — |
| GDPval | 42.5% | — |
| Remote Labor Index | 2.1% | — |
| τ²-bench Airline | 72% | — |
| τ²-bench Banking | 25.3% | — |
| τ²-bench Retail | 72.4% | — |
| τ²-bench Telecom | 84.9% | — |
| Cybench | 60% | — |
| DeepResearch Bench | 52.6% | — |
| OSWorld | 62.9% | — |
| GDP.pdf | — | 16% |
| LMArena Search | 1159 | — |
| METR Time Horizons | 67.4% | — |
| Vending-Bench 2 | 3,839 | — |

## Reasoning

- Claude Sonnet 4.5: 26.9 (#125)
- Muse Spark 1.2: 51.3 (#34)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| SimpleBench | 54.3% | 74.5% |
| NYT Connections (extended) | 37.3% | 79.2% |
| CritPt | 1.1% | 17.7% |
| LMArena Hard Prompts | 1462 | 1486 |
| DTBench | 83.2% | 94.7% |
| LMCA | 38.8% | 48.4% |
| Epoch Capabilities Index | 146.84 | 154.87 |
| ARC-AGI-2 | 13.6% | — |
| Kagi LLM Benchmark | 57.9% | — |
| ARC-AGI-1 | 63.7% | — |
| Chess Puzzles | 12% | — |
| EnigmaEval | 6% | — |
| EBR-Bench | 2.4% | — |
| Mystery Game Puzzles | 17% | — |
| ForecastBench | 61.9 | — |

## Math

- Claude Sonnet 4.5: 32.3 (#216)
- Muse Spark 1.2: 46.4 (#70)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| ProofBench | 19% | 43% |
| LMArena Math | 1449 | 1471 |
| FrontierMath (Tiers 1-3) | 23.9% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 77.8% | — |
| Omni-MATH | 55.3% | — |
| MATH Level 5 | 97.7% | — |
| FrontierMath (Feb 2025 set) | 15.2% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Claude Sonnet 4.5: 48.4 (#76)
- Muse Spark 1.2: 54.1 (#53)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| SimpleQA Verified | 30.7% | 60.3% |
| LMArena Expert | 1482 | 1480 |
| GPQA Diamond | 82.3% | — |
| Humanity's Last Exam | 13.7% | — |
| MMLU-Pro | 86.9% | — |
| Vectara Hallucination Rate | 12% | — |
| GPQA (HELM) | 68.6% | — |

## Multimodal

- Claude Sonnet 4.5: 34.8 (#89)
- Muse Spark 1.2: 43.4 (#25)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| LMArena Vision | — | 1305 |
| VPCT | 39.8% | — |
| LMArena Document | 1450 | — |

## Multilingual

- Claude Sonnet 4.5: 53.4 (#69)
- Muse Spark 1.2: 57.1 (#11)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| LMArena Non-English | 1425 | 1478 |
| LMArena Chinese | 1459 | 1511 |
| LMArena French | 1458 | 1513 |
| LMArena Russian | 1437 | 1487 |
| LMArena Spanish | 1457 | 1498 |
| LMArena German | 1427 | — |
| LMArena Japanese | 1390 | — |
| LMArena Korean | 1403 | — |

## Instruction Following

- Claude Sonnet 4.5: 75.0 (#78)
- Muse Spark 1.2: 76.7 (#36)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| LMArena Instruction Following | 1459 | 1461 |
| IFEval | 85% | — |

## Long Context

- Claude Sonnet 4.5: 45.2 (#46)
- Muse Spark 1.2: 45.2 (#48)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| LMArena Longer Query | 1476 | 1475 |

## Writing & Preference

- Claude Sonnet 4.5: 66.5 (#34)
- Muse Spark 1.2: 72.3 (#14)

| Benchmark | Claude Sonnet 4.5 | Muse Spark 1.2 |
|---|---|---|
| LMArena Text | 1439 | 1482 |
| LMArena Creative Writing | 1442 | 1449 |
| EQ-Bench Creative Writing | 1678 | 1840 |
| LMArena Multi-Turn | 1465 | 1494 |
| WildBench | 85.4% | — |

## FAQ

### Is Claude Sonnet 4.5 better than Muse Spark 1.2?

Muse Spark 1.2 is the stronger model overall, scoring 50.3 to 44.1 on the Noometry Index.

### Which is cheaper, Claude Sonnet 4.5 or Muse Spark 1.2?

Muse Spark 1.2 is cheaper. It lists at $1.25 per million input tokens and $4.25 per million output tokens; Claude Sonnet 4.5 lists at $3 and $15.

### Is Claude Sonnet 4.5 or Muse Spark 1.2 better for coding?

Muse Spark 1.2 scores higher on coding benchmarks: 49.2 versus 47.3 in the Noometry coding category.

### Which has the bigger context window?

Muse Spark 1.2 does, with 1.05M tokens against 200K.

### How many benchmarks do Claude Sonnet 4.5 and Muse Spark 1.2 share?

26 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and Muse Spark 1.2 has 31.