Model comparison
Claude Opus 5.5 vs Muse Spark 1.3
Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 54.8 on the Noometry Index. Muse Spark 1.3 costs 4.0× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.
Last verified . 31 shared benchmarks.
Summary
- They share 31 benchmarks with published results for both. Claude Opus 5.5 scores higher in 10 categories and Muse Spark 1.3 in 0 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 5.5 leads 80.2 to 54.0.
- The biggest single-benchmark swing is FrontierMath Tier 4: 95% for Claude Opus 5.5 and 46.3% for Muse Spark 1.3.
- Muse Spark 1.3 is cheaper at $1.25 / $4.25 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
- Muse Spark 1.3 accepts more context: 1.05M tokens versus 1M.
Side by side
| Claude Opus 5.5 | Muse Spark 1.3 | |
|---|---|---|
| Provider | Anthropic | Meta |
| Noometry Index | 68.6 | 54.8 |
| Released | 2026-09-22 | 2026-09-02 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 1.05M |
| Max output | 128K | 131K |
| Input $ / M tokens | $4 | $1.25 |
| Output $ / M tokens | $20 | $4.25 |
| Results tracked | 44 | 37 |
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Category by category
Coding Claude Opus 5.5 leads
Claude Opus 5.5: 71.9 (#3), Muse Spark 1.3: 56.6 (#21)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| CursorBench | 57.8% | 41.6% |
| LMArena WebDev | 1813 | 1657 |
| SciCode | 66.9% | 59.7% |
| LMArena Coding | 1547 | 1514 |
| FrontierCode | 54.6% | — |
| FrontierSWE | 62.3% | — |
| MirrorCode | 77.4% | — |
| ALE-Bench | 2,147 | — |
Agentic & Tool Use Claude Opus 5.5 leads
Claude Opus 5.5: 45.3 (#15), Muse Spark 1.3: 38.6 (#30)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| APEX-Agents | 73.5% | 57.8% |
| GDP.pdf | 30.6% | 27.6% |
| Vending-Bench 2 | 9,235 | — |
Reasoning Claude Opus 5.5 leads
Claude Opus 5.5: 80.2 (#3), Muse Spark 1.3: 54.0 (#27)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| NYT Connections (extended) | 88.5% | 85.1% |
| CritPt | 31.7% | 26% |
| LMArena Hard Prompts | 1535 | 1503 |
| Mystery Game Puzzles | 71% | 25% |
| DTBench | 98.9% | 96.5% |
| LMCA | 68.2% | 53.9% |
| Epoch Capabilities Index | 167.33 | 156.75 |
| ARC-AGI-2 | 93.3% | — |
| ARC-AGI-1 | 98.5% | — |
| Chess Puzzles | — | 38% |
| EBR-Bench | 71.4% | — |
| Bench to the Future 3 | — | 0.14 |
Math Claude Opus 5.5 leads
Claude Opus 5.5: 91.8 (#3), Muse Spark 1.3: 73.1 (#21)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 91.2% | 74.4% |
| FrontierMath Tier 4 | 95% | 46.3% |
| OTIS Mock AIME 2024-2025 | 100% | 99.2% |
| ProofBench | 100% | 58% |
| LMArena Math | 1506 | 1494 |
| FrontierMath Erdős | 2.9% | — |
Knowledge Claude Opus 5.5 leads
Claude Opus 5.5: 66.4 (#10), Muse Spark 1.3: 42.6 (#95)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| LMArena Expert | 1547 | 1516 |
| GPQA Diamond | 90.6% | — |
| SimpleQA Verified | 72.2% | — |
Multimodal Claude Opus 5.5 leads
Claude Opus 5.5: 57.8 (#1), Muse Spark 1.3: 43.7 (#22)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| LMArena Vision | 1321 | 1309 |
| Blueprint-Bench 2 | 51.2% | — |
| Furniture Assembly | 83.3% | — |
| LMArena Document | — | 1471 |
Multilingual Claude Opus 5.5 leads
Claude Opus 5.5: 59.1 (#2), Muse Spark 1.3: 57.4 (#8)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| LMArena Non-English | 1507 | 1481 |
| LMArena Chinese | 1588 | 1529 |
| LMArena French | 1514 | 1524 |
| LMArena Russian | 1520 | 1490 |
| LMArena Spanish | 1507 | 1490 |
| LMArena German | — | 1515 |
| LMArena Japanese | — | 1474 |
| LMArena Korean | — | 1501 |
Instruction Following Claude Opus 5.5 leads
Claude Opus 5.5: 80.0 (#3), Muse Spark 1.3: 77.5 (#22)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| LMArena Instruction Following | 1537 | 1477 |
Long Context Claude Opus 5.5 leads
Claude Opus 5.5: 47.1 (#19), Muse Spark 1.3: 45.6 (#32)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| LMArena Longer Query | 1532 | 1488 |
Writing & Preference Claude Opus 5.5 leads
Claude Opus 5.5: 78.2 (#3), Muse Spark 1.3: 73.6 (#9)
| Benchmark | Claude Opus 5.5 | Muse Spark 1.3 |
|---|---|---|
| LMArena Text | 1515 | 1490 |
| LMArena Creative Writing | 1533 | 1455 |
| EQ-Bench Creative Writing | 2050 | 1906 |
| LMArena Multi-Turn | 1499 | 1482 |
Frequently asked questions
Is Claude Opus 5.5 better than Muse Spark 1.3?
Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 54.8 on the Noometry Index. Muse Spark 1.3 costs 4.0× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 5.5 or Muse Spark 1.3?
Muse Spark 1.3 is cheaper. It lists at $1.25 per million input tokens and $4.25 per million output tokens; Claude Opus 5.5 lists at $4 and $20.
Is Claude Opus 5.5 or Muse Spark 1.3 better for coding?
Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 56.6 in the Noometry coding category.
Which has the bigger context window?
Muse Spark 1.3 does, with 1.05M tokens against 1M.
How many benchmarks do Claude Opus 5.5 and Muse Spark 1.3 share?
31 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Muse Spark 1.3 has 37.