Muse Spark 1.2 vs Solar Pro 4
Muse Spark 1.2 leads Solar Pro 4 on the Artificial Analysis Intelligence Index, 39.6 to 28.2, and Solar Pro 4 costs 7.1x less per output token ($0.60 vs $4.25 per million). Updated October 22, 2026; 41 benchmarks have a result for both.
Muse Spark 1.2 or Solar Pro 4: which to pick
Only Muse Spark 1.2 has a coding score, 55.7 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding.
Pick Solar Pro 4 for output tokens 7.1x cheaper ($0.60 vs $4.25 per million).
- Shared results
- 41
- Muse Spark 1.2 only
- 56
- Solar Pro 4 only
- 4
- Like-for-like categories
- 8 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
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, six public coding benchmarks
No call
Only Muse Spark 1.2 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Muse Spark 1.2
Muse Spark 1.2 leads, 39.6 against 28.2.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Muse Spark 1.2 has a AA Agentic Index result, 43.2.
Directional only
Knowledge
MMLU Pro
No call
Only Muse Spark 1.2 has a MMLU Pro result, 88.3%.
Directional only
Web design
Design Arena: websites
Muse Spark 1.2
Muse Spark 1.2 leads, 1312 against 1176.
Same board, both measured
Long documents
Listed context window
Muse Spark 1.2
Muse Spark 1.2 takes 1.05M tokens against 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Solar Pro 4
Muse Spark 1.2 $0.0034, Solar Pro 4 $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Muse Spark 1.2 has the number, $0.64.
Directional only
At a glance
- Coding index
- Muse Spark 1.2 55.7 from 5 benchmarks, Solar Pro 4 not benchmarked.
- Widest category
- Knowledge, 19.0 points apart on average over 4 shared benchmarks.
- Widest single gap
- LMArena WebDev: HTML: Muse Spark 1.2 1543 against Solar Pro 4 1371, 28.7 points apart on a 0 to 100 scale.
- Output price
- Muse Spark 1.2 $4.25 against Solar Pro 4 $0.60 per million output tokens, 7.1x apart.
- Context window
- Muse Spark 1.2 takes 1.05M tokens, Solar Pro 4 524K.
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 | Muse Spark 1.2 | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 5 | 0 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 0 | ||
| Web design | 6 | 0 | ||
| General | 15 | 0 | ||
| All shared boards | 41 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| LiveBench coding | 78.2% | Not measured | Only Muse Spark 1.2 measured |
| LMArena WebDev | 1534 | 1371 | Muse Spark 1.2 |
| AA Coding Index | 72.2 | 52.7 | Muse Spark 1.2 |
| SWE-bench Verified (Vals AI) | 86.6% | Not measured | Only Muse Spark 1.2 measured |
| Terminal-Bench 4 (Vals AI) | 6.1% | Not measured | Only Muse Spark 1.2 measured |
| Vibe Code Bench (Vals AI) | 79.1% | Not measured | Only Muse Spark 1.2 measured |
| Code migration (Vals AI) | 29.9% | Not measured | Only Muse Spark 1.2 measured |
| ProgramBench (Vals AI) | 0.5% | Not measured | Only Muse Spark 1.2 measured |
| IOI (Vals AI) | 21.8% | Not measured | Only Muse Spark 1.2 measured |
| Terminal-Bench 2.1 (Vals AI) | 69.7% | Not measured | Only Muse Spark 1.2 measured |
| SkillsBench (Vals AI) | 53.0% | Not measured | Only Muse Spark 1.2 measured |
| CyberBench (Vals AI) | 69.5% | Not measured | Only Muse Spark 1.2 measured |
| SciCode | 57.4% | 48.0% | Muse Spark 1.2 |
| FrontierSWE | 12.0% | Not measured | Only Muse Spark 1.2 measured |
| WeirdML | 60.3% | Not measured | Only Muse Spark 1.2 measured |
| ALE-Bench | Not measured | 179.3 | Only Solar Pro 4 measured |
| LMArena Text: coding | 1505 | 1438 | Muse Spark 1.2 |
| LMArena Text: software and IT | 1505 | 1431 | Muse Spark 1.2 |
| LMArena WebDev: React | 1526 | 1363 | Muse Spark 1.2 |
| LMArena WebDev: HTML | 1543 | 1371 | Muse Spark 1.2 |
| Neither model has a result on the other 19 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 39.6 | 28.2 | Muse Spark 1.2 |
| Epoch Capabilities Index | 155.1 | Not measured | Only Muse Spark 1.2 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Agentic Index | 43.2 | Not measured | Only Muse Spark 1.2 measured |
| Design Arena: agents building web apps | 1221 | 1105 | Muse Spark 1.2 |
| Design Arena: agents building full-stack apps | 1210 | Not measured | Only Muse Spark 1.2 measured |
| Design Arena: agents building mobile apps | 1181 | Not measured | Only Muse Spark 1.2 measured |
| Design Arena: agents building Android apps | 1222 | Not measured | Only Muse Spark 1.2 measured |
| Design Arena: agents building games | 1179 | Not measured | Only Muse Spark 1.2 measured |
| Design Arena: HTML slides | 1085 | Not measured | Only Muse Spark 1.2 measured |
| Design Arena: PowerPoint slides | 1172 | Not measured | Only Muse Spark 1.2 measured |
| LiveBench research | 67.7% | Not measured | Only Muse Spark 1.2 measured |
| LiveBench browser | 36.0% | Not measured | Only Muse Spark 1.2 measured |
| LiveBench long agentic | 21.3% | Not measured | Only Muse Spark 1.2 measured |
| SREBench (Vals AI) | 0.0% | Not measured | Only Muse Spark 1.2 measured |
| Finance Agent (Vals AI) | 60.6% | Not measured | Only Muse Spark 1.2 measured |
| Tax Agent Bench (Vals AI) | 32.8% | Not measured | Only Muse Spark 1.2 measured |
| Legal Research Bench (Vals AI) | 43.8% | Not measured | Only Muse Spark 1.2 measured |
| Excel Modeling Benchmark (Vals AI) | 57.0% | Not measured | Only Muse Spark 1.2 measured |
| BioMysteryBench (Vals AI) | 64.8% | Not measured | Only Muse Spark 1.2 measured |
| APEX-Agents | 45.4% | Not measured | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 23 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| LiveBench reasoning | 90.0% | Not measured | Only Muse Spark 1.2 measured |
| MMMU Pro (Vals AI) | 86.1% | Not measured | Only Muse Spark 1.2 measured |
| GPQA Diamond (Artificial Analysis run) | 90.4% | 89.1% | Muse Spark 1.2 |
| Humanity's Last Exam (Artificial Analysis run) | 45.5% | 29.8% | Muse Spark 1.2 |
| SimpleBench | 74.5% | Not measured | Only Muse Spark 1.2 measured |
| Chess puzzles | 27.0% | Not measured | Only Muse Spark 1.2 measured |
| LMArena Text: hard prompts | 1489 | 1400 | Muse Spark 1.2 |
| LMArena Text: expert | 1475 | 1428 | Muse Spark 1.2 |
| LMArena Text: hard prompts in English | 1487 | 1427 | Muse Spark 1.2 |
| LMArena Vision: diagrams | 1317 | Not measured | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 12 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| ProofBench | 43.0% | Not measured | Only Muse Spark 1.2 measured |
| LMArena Text: math | 1484 | 1421 | Muse Spark 1.2 |
| LMArena Text: mathematical work | 1480 | 1427 | Muse Spark 1.2 |
| Neither model has a result on the other 10 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| MMLU Pro | 88.3% | Not measured | Only Muse Spark 1.2 measured |
| LegalBench (Vals AI) | 85.3% | Not measured | Only Muse Spark 1.2 measured |
| CorpFin (Vals AI) | 70.9% | Not measured | Only Muse Spark 1.2 measured |
| TaxEval (Vals AI) | 80.4% | Not measured | Only Muse Spark 1.2 measured |
| MortgageTax (Vals AI) | 65.4% | Not measured | Only Muse Spark 1.2 measured |
| MedCode (Vals AI) | 49.4% | Not measured | Only Muse Spark 1.2 measured |
| SimpleQA Verified | 60.3% | Not measured | Only Muse Spark 1.2 measured |
| LMArena Text: science | 1500 | 1404 | Muse Spark 1.2 |
| LMArena Text: medicine and healthcare | 1496 | 1374 | Muse Spark 1.2 |
| LMArena Text: legal and government | 1517 | 1383 | Muse Spark 1.2 |
| LMArena Text: business and finance | 1484 | 1381 | Muse Spark 1.2 |
| Neither model has a result on the other 7 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1312 | 1176 | Muse Spark 1.2 |
| Design Arena: UI components | 1298 | 1147 | Muse Spark 1.2 |
| Design Arena: game dev | 1301 | 1169 | Muse Spark 1.2 |
| Design Arena: data viz | 1334 | 1177 | Muse Spark 1.2 |
| Design Arena: 3D | 1301 | 1178 | Muse Spark 1.2 |
| Design Arena: all code categories | 1312 | 1182 | Muse Spark 1.2 |
| Design Arena: SVG | 1284 | Not measured | Only Muse Spark 1.2 measured |
| Design Arena: ASCII art | 1284 | Not measured | Only Muse Spark 1.2 measured |
| LiveBench design | 67.1% | Not measured | Only Muse Spark 1.2 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index150
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | Leader |
|---|---|---|---|
| LiveBench data analysis | 76.5% | Not measured | Only Muse Spark 1.2 measured |
| Public Benefits Bench (Vals AI) | 68.5% | Not measured | Only Muse Spark 1.2 measured |
| SAGE (Vals AI) | 47.7% | Not measured | Only Muse Spark 1.2 measured |
| MedScribe (Vals AI) | 90.1% | Not measured | Only Muse Spark 1.2 measured |
| Vals Multimodal Index | 69.8% | Not measured | Only Muse Spark 1.2 measured |
| Long context reasoning (AA-LCR) | 79.0% | 70.7% | Muse Spark 1.2 |
| DTBench | 94.7% | Not measured | Only Muse Spark 1.2 measured |
| LMCA | 48.4% | Not measured | Only Muse Spark 1.2 measured |
| LMArena Text | 1482 | 1388 | Muse Spark 1.2 |
| LMArena Text: instruction following | 1462 | 1375 | Muse Spark 1.2 |
| LMArena Text: creative writing | 1436 | 1317 | Muse Spark 1.2 |
| LMArena Vision | 1304 | Not measured | Only Muse Spark 1.2 measured |
| LMArena Text: English | 1483 | 1414 | Muse Spark 1.2 |
| LMArena Text: non-English | 1476 | 1363 | Muse Spark 1.2 |
| LMArena Text: Chinese | 1509 | 1422 | Muse Spark 1.2 |
| LMArena Text: German | Not measured | 1358 | Only Solar Pro 4 measured |
| LMArena Text: Japanese | Not measured | 1320 | Only Solar Pro 4 measured |
| LMArena Text: Korean | 1462 | 1383 | Muse Spark 1.2 |
| LMArena Text: French | 1495 | 1400 | Muse Spark 1.2 |
| LMArena Text: Spanish | 1484 | 1409 | Muse Spark 1.2 |
| LMArena Text: Russian | 1483 | 1357 | Muse Spark 1.2 |
| LMArena Text: Polish | Not measured | 1304 | Only Solar Pro 4 measured |
| LMArena Text: multi-turn | 1502 | 1385 | Muse Spark 1.2 |
| LMArena Text: longer queries | 1473 | 1382 | Muse Spark 1.2 |
| LMArena Text: writing and language | 1453 | 1344 | Muse Spark 1.2 |
| LMArena Text: entertainment and media | 1443 | 1332 | Muse Spark 1.2 |
| LMArena Vision: English | 1291 | Not measured | Only Muse Spark 1.2 measured |
| LMArena Vision: reading text | 1313 | Not measured | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 18 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark 1.2 | Solar Pro 4 | 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
Solar Pro 4 costs less
Repository review
50K input + 3K output tokens
Solar Pro 4 costs less
Agent loop
200K input + 10K output tokens
Solar Pro 4 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 | Meta Muse Spark 1.2 | Upstage Solar Pro 4 |
|---|---|---|
| Maker | Meta | Upstage |
| Weights | No public weights listed | No public weights listed |
| Released | August 5, 2026 | August 10, 2026 |
| Context window | 1.05M | 524K |
| Input $/Mtok | $1.25 | $0.15 |
| Output $/Mtok | $4.25 | $0.60 |
| Coding index | 55.7 | Not benchmarked |
| Independent measurements behind it | 5 | 1 |
| Cost per solved task | $0.64 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark 1.2 better than Solar Pro 4 for coding?
Only Muse Spark 1.2 has a coding score, 55.7 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding. Pick Solar Pro 4 for output tokens 7.1x cheaper ($0.60 vs $4.25 per million).
Which is cheaper, Muse Spark 1.2 or Solar Pro 4?
Muse Spark 1.2 costs $1.25 per million input tokens and $4.25 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for Muse Spark 1.2 only.
Which has the bigger context window, Muse Spark 1.2 or Solar Pro 4?
Muse Spark 1.2, with 1.05M tokens against 524K.
How many benchmarks is the Muse Spark 1.2 vs Solar Pro 4 comparison based on?
41 benchmarks have a result for both models as of October 22, 2026. Muse Spark 1.2's coding index rests on 5 independent benchmarks and Solar Pro 4's on 1. Where only one model has a result, the page says so instead of naming a winner.