Claude Opus 4.5 vs Muse Spark 1.3
Updated October 21, 2026. 56 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
vs boards won of 56 shared
Decision reading
Pick Muse Spark 1.3 for coding: it scores 79.7 on the Vibe Coding Index against 66.8 for Claude Opus 4.5.
Claude Opus 4.5 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Model AClaude Opus 4.5Anthropic66.8/1002 independent benchmarks$1.37 per solved taskModel BMuse Spark 1.3Meta79.7/1002 independent benchmarksNo cost per solved task
- Shared results
- 56
- Claude Opus 4.5 only
- 49
- Muse Spark 1.3 only
- 36
- Like-for-like categories
- 8 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, four public coding benchmarks
Muse Spark 1.3
Muse Spark 1.3 scores 79.7 against 66.8.
2 benchmarks behind each score
Intelligence
AA Intelligence Index
Muse Spark 1.3
Muse Spark 1.3 leads, 48.1 against 29.1.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Muse Spark 1.3 has a AA Agentic Index result, 55.5.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Opus 4.5 has a GPQA Diamond result, 85.9%.
Directional only
Math
AIME
No call
Only Claude Opus 4.5 has a AIME result, 95.4%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Opus 4.5 has a MMLU Pro result, 87.3%.
Directional only
Web design
Design Arena: websites
Muse Spark 1.3
Muse Spark 1.3 leads, 1356 against 1247.
Same board, both measured
Long documents
Listed context window
Muse Spark 1.3
Muse Spark 1.3 takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Spark 1.3
Claude Opus 4.5 $0.018, Muse Spark 1.3 $0.0034 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Opus 4.5 has the number, $1.37.
Directional only
At a glance
- Coding index
- Claude Opus 4.5 66.8 from 2 benchmarks, Muse Spark 1.3 79.7 from 2 benchmarks.
- Widest category
- Coding, 21.1 points apart on average over 6 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Claude Opus 4.5 20.6% against Muse Spark 1.3 82.9%, 62.2 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.5 $25.00 against Muse Spark 1.3 $4.25 per million output tokens, 5.9x apart.
- Context window
- Claude Opus 4.5 takes 200K tokens, Muse Spark 1.3 1.05M.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Claude Opus 4.5 | Bars | Muse Spark 1.3 | Ties |
|---|---|---|---|---|
| Coding | 0 | 6 | ||
| Intelligence | 0 | 2 | ||
| Agentic work | 0 | 3 | ||
| Reasoning | 0 | 7 | ||
| Math | 0 | 6 | ||
| Knowledge | 0 | 4 | ||
| Web design | 0 | 8 | ||
| General | 0 | 20 | ||
| All shared boards | 0 | 56 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index06
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| SWE-bench Verified | 79.2% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench (full test set) | 52.6% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench Multilingual | 70.7% | Not measured | Only Claude Opus 4.5 measured |
| LiveBench coding | Not measured | 90.2% | Only Muse Spark 1.3 measured |
| LMArena WebDev | 1494 | 1659 | Muse Spark 1.3 |
| AA Coding Index | Not measured | 75.8 | Only Muse Spark 1.3 measured |
| LiveCodeBench (Vals AI) | 83.7% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench Verified (Vals AI) | 76.4% | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 10.6% | Only Muse Spark 1.3 measured |
| Vibe Code Bench (Vals AI) | 20.6% | 82.9% | Muse Spark 1.3 |
| Code migration (Vals AI) | Not measured | 27.6% | Only Muse Spark 1.3 measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Muse Spark 1.3 measured |
| IOI (Vals AI) | Not measured | 43.9% | Only Muse Spark 1.3 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 72.3% | Only Muse Spark 1.3 measured |
| CyberBench (Vals AI) | Not measured | 69.4% | Only Muse Spark 1.3 measured |
| LiveCodeBench (Artificial Analysis run) | 87.1% | Not measured | Only Claude Opus 4.5 measured |
| SciCode | Not measured | 59.7% | Only Muse Spark 1.3 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 47.0% | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench | 63.1% | Not measured | Only Claude Opus 4.5 measured |
| FrontierSWE | Not measured | 25.8% | Only Muse Spark 1.3 measured |
| GSO-Bench | 26.5% | Not measured | Only Claude Opus 4.5 measured |
| WeirdML | 63.7% | Not measured | Only Claude Opus 4.5 measured |
| Cybench | 82.0% | Not measured | Only Claude Opus 4.5 measured |
| ALE-Bench | Not measured | 1688.3 | Only Muse Spark 1.3 measured |
| LMArena Text: coding | 1503 | 1510 | Muse Spark 1.3 |
| LMArena Text: software and IT | 1483 | 1511 | Muse Spark 1.3 |
| LMArena WebDev: React | 1478 | 1672 | Muse Spark 1.3 |
| LMArena WebDev: HTML | 1510 | 1653 | Muse Spark 1.3 |
| LMArena WebDev: from an image | Not measured | 1640 | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 9 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| AA Intelligence Index | 29.1 | 48.1 | Muse Spark 1.3 |
| Epoch Capabilities Index | 150.1 | 157.2 | Muse Spark 1.3 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 55.5 | Only Muse Spark 1.3 measured |
| Design Arena: agents building web apps | 1159 | 1297 | Muse Spark 1.3 |
| Design Arena: agents building full-stack apps | 1156 | 1295 | Muse Spark 1.3 |
| Design Arena: agents building mobile apps | 1189 | 1217 | Muse Spark 1.3 |
| Design Arena: agents building Android apps | 1181 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: agents building Godot games | Not measured | 1241 | Only Muse Spark 1.3 measured |
| Design Arena: PowerPoint slides | Not measured | 1244 | Only Muse Spark 1.3 measured |
| Design Arena: spreadsheets | Not measured | 1048 | Only Muse Spark 1.3 measured |
| LiveBench research | Not measured | 68.6% | Only Muse Spark 1.3 measured |
| LiveBench browser | Not measured | 80.0% | Only Muse Spark 1.3 measured |
| LiveBench long agentic | Not measured | 40.4% | Only Muse Spark 1.3 measured |
| Finance Agent (Vals AI) | Not measured | 58.9% | Only Muse Spark 1.3 measured |
| Tax Agent Bench (Vals AI) | Not measured | 36.0% | Only Muse Spark 1.3 measured |
| Legal Research Bench (Vals AI) | Not measured | 40.9% | Only Muse Spark 1.3 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 62.7% | Only Muse Spark 1.3 measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 4.3% | Only Muse Spark 1.3 measured |
| τ²-Bench Telecom | 89.5% | Not measured | Only Claude Opus 4.5 measured |
| APEX-Agents | Not measured | 58.6% | Only Muse Spark 1.3 measured |
| METR time horizons | 75.0% | Not measured | Only Claude Opus 4.5 measured |
| Remote Labor Index | 3.8% | Not measured | Only Claude Opus 4.5 measured |
| GDPval | 45.5% | Not measured | Only Claude Opus 4.5 measured |
| BALROG | 43.5% | Not measured | Only Claude Opus 4.5 measured |
| DeepResearch Bench | 54.8% | Not measured | Only Claude Opus 4.5 measured |
| OSWorld | 66.3% | Not measured | Only Claude Opus 4.5 measured |
| Vending-Bench 2 | $4,967 | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 14 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index07
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| GPQA Diamond | 85.9% | Not measured | Only Claude Opus 4.5 measured |
| LiveBench reasoning | Not measured | 89.7% | Only Muse Spark 1.3 measured |
| MMMU Pro (Vals AI) | 83.0% | Not measured | Only Claude Opus 4.5 measured |
| GPQA Diamond (Artificial Analysis run) | 86.6% | 94.1% | Muse Spark 1.3 |
| Humanity's Last Exam (Artificial Analysis run) | 30.1% | 48.7% | Muse Spark 1.3 |
| GPQA Diamond (Epoch AI run) | 86.0% | Not measured | Only Claude Opus 4.5 measured |
| ARC-AGI | 80.0% | Not measured | Only Claude Opus 4.5 measured |
| ARC-AGI-2 | 37.6% | Not measured | Only Claude Opus 4.5 measured |
| SimpleBench | 62.0% | Not measured | Only Claude Opus 4.5 measured |
| Chess puzzles | 14.0% | 37.0% | Muse Spark 1.3 |
| Mystery game puzzles | 22.0% | 25.0% | Muse Spark 1.3 |
| EBR-bench | 14.3% | Not measured | Only Claude Opus 4.5 measured |
| VPCT | 40.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: hard prompts | 1476 | 1503 | Muse Spark 1.3 |
| LMArena Text: expert | 1487 | 1519 | Muse Spark 1.3 |
| LMArena Text: hard prompts in English | 1482 | 1500 | Muse Spark 1.3 |
| LMArena Vision: diagrams | Not measured | 1330 | Only Muse Spark 1.3 measured |
| LMArena Vision: homework | Not measured | 1296 | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 3 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| AIME | 95.4% | Not measured | Only Claude Opus 4.5 measured |
| MGSM (Vals AI) | 95.2% | Not measured | Only Claude Opus 4.5 measured |
| AA Math Index | 91.3 | Not measured | Only Claude Opus 4.5 measured |
| AIME 2025 (Artificial Analysis run) | 91.3% | Not measured | Only Claude Opus 4.5 measured |
| OTIS Mock AIME | 86.1% | 99.2% | Muse Spark 1.3 |
| FrontierMath, tiers 1 to 3 | 34.4% | 74.4% | Muse Spark 1.3 |
| FrontierMath, tier 4 | 4.9% | 46.3% | Muse Spark 1.3 |
| ProofBench | 36.0% | 58.0% | Muse Spark 1.3 |
| LMArena Text: math | 1463 | 1497 | Muse Spark 1.3 |
| LMArena Text: mathematical work | 1468 | 1491 | Muse Spark 1.3 |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| MMLU Pro | 87.3% | Not measured | Only Claude Opus 4.5 measured |
| LegalBench (Vals AI) | 84.6% | Not measured | Only Claude Opus 4.5 measured |
| CaseLaw (Vals AI) | 62.6% | Not measured | Only Claude Opus 4.5 measured |
| CorpFin (Vals AI) | 65.1% | Not measured | Only Claude Opus 4.5 measured |
| TaxEval (Vals AI) | 74.9% | Not measured | Only Claude Opus 4.5 measured |
| MortgageTax (Vals AI) | 68.7% | Not measured | Only Claude Opus 4.5 measured |
| MedQA (Vals AI) | 95.9% | Not measured | Only Claude Opus 4.5 measured |
| MedCode (Vals AI) | 49.2% | Not measured | Only Claude Opus 4.5 measured |
| MMLU Pro (Artificial Analysis run) | 89.5% | Not measured | Only Claude Opus 4.5 measured |
| SimpleQA Verified | 45.7% | Not measured | Only Claude Opus 4.5 measured |
| GeoBench | 75.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: science | 1454 | 1507 | Muse Spark 1.3 |
| LMArena Text: medicine and healthcare | 1444 | 1493 | Muse Spark 1.3 |
| LMArena Text: legal and government | 1459 | 1499 | Muse Spark 1.3 |
| LMArena Text: business and finance | 1448 | 1490 | Muse Spark 1.3 |
| Neither model has a result on the other 2 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| Design Arena: websites | 1247 | 1356 | Muse Spark 1.3 |
| Design Arena: UI components | 1238 | 1352 | Muse Spark 1.3 |
| Design Arena: game dev | 1229 | 1329 | Muse Spark 1.3 |
| Design Arena: data viz | 1243 | 1343 | Muse Spark 1.3 |
| Design Arena: 3D | 1214 | 1359 | Muse Spark 1.3 |
| Design Arena: all code categories | 1242 | 1353 | Muse Spark 1.3 |
| Design Arena: SVG | 1180 | 1300 | Muse Spark 1.3 |
| Design Arena: ASCII art | 1190 | 1280 | Muse Spark 1.3 |
| LiveBench design | Not measured | 74.8% | Only Muse Spark 1.3 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index020
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 79.6% | Only Muse Spark 1.3 measured |
| SAGE (Vals AI) | 52.1% | Not measured | Only Claude Opus 4.5 measured |
| MedScribe (Vals AI) | 85.3% | Not measured | Only Claude Opus 4.5 measured |
| IFBench | 58.0% | Not measured | Only Claude Opus 4.5 measured |
| Long context reasoning (AA-LCR) | 77.3% | 83.0% | Muse Spark 1.3 |
| DTBench | 89.9% | 96.5% | Muse Spark 1.3 |
| LMCA | 44.5% | 53.9% | Muse Spark 1.3 |
| CL-bench | 21.1% | Not measured | Only Claude Opus 4.5 measured |
| Furniture assembly | 28.3% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text | 1451 | 1490 | Muse Spark 1.3 |
| LMArena Text: instruction following | 1478 | 1479 | Muse Spark 1.3 |
| LMArena Text: creative writing | 1445 | 1462 | Muse Spark 1.3 |
| LMArena Vision | Not measured | 1308 | Only Muse Spark 1.3 measured |
| LMArena Text: English | 1461 | 1495 | Muse Spark 1.3 |
| LMArena Text: non-English | 1438 | 1481 | Muse Spark 1.3 |
| LMArena Text: Chinese | 1470 | 1532 | Muse Spark 1.3 |
| LMArena Text: German | 1449 | 1513 | Muse Spark 1.3 |
| LMArena Text: Japanese | 1417 | 1470 | Muse Spark 1.3 |
| LMArena Text: Korean | 1424 | 1490 | Muse Spark 1.3 |
| LMArena Text: French | 1471 | 1511 | Muse Spark 1.3 |
| LMArena Text: Spanish | 1457 | 1496 | Muse Spark 1.3 |
| LMArena Text: Russian | 1447 | 1491 | Muse Spark 1.3 |
| LMArena Text: Polish | 1439 | 1490 | Muse Spark 1.3 |
| LMArena Text: multi-turn | 1466 | 1487 | Muse Spark 1.3 |
| LMArena Text: longer queries | 1479 | 1488 | Muse Spark 1.3 |
| LMArena Text: writing and language | 1452 | 1470 | Muse Spark 1.3 |
| LMArena Text: entertainment and media | 1434 | 1457 | Muse Spark 1.3 |
| LMArena Vision: English | Not measured | 1298 | Only Muse Spark 1.3 measured |
| LMArena Vision: Chinese | Not measured | 1384 | Only Muse Spark 1.3 measured |
| LMArena Vision: reading text | Not measured | 1319 | Only Muse Spark 1.3 measured |
| LMArena Vision: humor | Not measured | 1293 | Only Muse Spark 1.3 measured |
| LMArena Vision: creative writing | Not measured | 1296 | Only Muse Spark 1.3 measured |
| LMArena Document | 1462 | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 13 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 4.5 | Muse Spark 1.3 | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Claude Opus 4.5$0.018Fits in one request
Muse Spark 1.3$0.0034Fits in one request
Muse Spark 1.3 costs less
Repository review
50K input + 3K output tokens
Claude Opus 4.5$0.325Fits in one request
Muse Spark 1.3$0.075Fits in one request
Muse Spark 1.3 costs less
Agent loop
200K input + 10K output tokens
Claude Opus 4.5$1.25Exceeds the context window
Muse Spark 1.3$0.292Fits in one request
Muse Spark 1.3 costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Anthropic Claude Opus 4.5 | Meta Muse Spark 1.3 |
|---|---|---|
| Maker | Anthropic | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | November 24, 2025 | September 2, 2026 |
| Context window | 200K | 1.05M |
| Input $/Mtok | $5.00 | $1.25 |
| Output $/Mtok | $25.00 | $4.25 |
| Coding index | 66.8 | 79.7 |
| Independent measurements behind it | 2 | 2 |
| Cost per solved task | $1.37 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.5 better than Muse Spark 1.3 for coding?
Pick Muse Spark 1.3 for coding: it scores 79.7 on the Vibe Coding Index against 66.8 for Claude Opus 4.5. Claude Opus 4.5 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Which is cheaper, Claude Opus 4.5 or Muse Spark 1.3?
Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; Muse Spark 1.3 costs $1.25 and $4.25. Cost per solved task is known for Claude Opus 4.5 only.
Which has the bigger context window, Claude Opus 4.5 or Muse Spark 1.3?
Muse Spark 1.3, with 1.05M tokens against 200K.
How many benchmarks is the Claude Opus 4.5 vs Muse Spark 1.3 comparison based on?
56 benchmarks have a result for both models as of October 21, 2026. Claude Opus 4.5's coding index rests on 2 independent benchmarks and Muse Spark 1.3's on 2. Where only one model has a result, the page says so instead of naming a winner.