Muse Spark 1.1 vs Step 5 Preview
Muse Spark 1.1 leads Step 5 Preview on coding, 70.3 to 61.1 on the Vibe Coding Index, and Step 5 Preview costs 1.6x less per output token ($2.70 vs $4.25 per million). Updated October 22, 2026; 45 benchmarks have a result for both.
Muse Spark 1.1 or Step 5 Preview: which to pick
Pick Muse Spark 1.1 for coding: it scores 70.3 on the Vibe Coding Index against 61.1 for Step 5 Preview, though on 3 benchmarks against 4.
Pick Step 5 Preview for output tokens 1.6x cheaper ($2.70 vs $4.25 per million) and work measured by LMArena WebDev or Code migration (Vals AI), where it leads.
- Shared results
- 45
- Muse Spark 1.1 only
- 51
- Step 5 Preview only
- 16
- Like-for-like categories
- 7 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
Muse Spark 1.1
Muse Spark 1.1 scores 70.3 against 61.1.
3 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
Step 5 Preview
Step 5 Preview leads, 43.7 against 33.7.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Muse Spark 1.1 has a AA Agentic Index result, 25.8.
Directional only
Reasoning
GPQA Diamond
No call
Only Muse Spark 1.1 has a GPQA Diamond result, 91.2%.
Directional only
Knowledge
MMLU Pro
No call
Only Muse Spark 1.1 has a MMLU Pro result, 88.7%.
Directional only
Web design
Design Arena: websites
No call
Only Muse Spark 1.1 has a Design Arena: websites result, 1270.
Directional only
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 5 Preview
Muse Spark 1.1 $0.0034, Step 5 Preview $0.0024 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Muse Spark 1.1 has the number, $0.43.
Directional only
At a glance
- Coding index
- Muse Spark 1.1 70.3 from 3 benchmarks, Step 5 Preview 61.1 from 4 benchmarks.
- Widest category
- Intelligence, 10.0 points apart on average over 1 shared benchmark.
- Widest single gap
- LMArena Text: Japanese: Muse Spark 1.1 1450 against Step 5 Preview 1383, 11.0 points apart on a 0 to 100 scale.
- Output price
- Muse Spark 1.1 $4.25 against Step 5 Preview $2.70 per million output tokens, 1.6x apart.
- Context window
- Both take 1.05M tokens.
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 1.1 | Bars | Step 5 Preview | Ties |
|---|---|---|---|---|
| Coding | 3 | 6 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 1 | 2 | ||
| Reasoning | 3 | 3 | ||
| Math | 2 | 1 | ||
| Knowledge | 4 | 0 | ||
| General | 18 | 1 | ||
| All shared boards | 31 | 14 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index36
| Benchmark | Muse Spark 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 85.6% | Only Step 5 Preview measured |
| LMArena WebDev | 1542 | 1567 | Step 5 Preview |
| AA Coding Index | 71.3 | Not measured | Only Muse Spark 1.1 measured |
| LiveCodeBench (Vals AI) | 85.9% | Not measured | Only Muse Spark 1.1 measured |
| SWE-bench Verified (Vals AI) | 82.0% | Not measured | Only Muse Spark 1.1 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 31.8% | Only Step 5 Preview measured |
| Vibe Code Bench (Vals AI) | 72.2% | 70.4% | Muse Spark 1.1 |
| Code migration (Vals AI) | 31.1% | 39.0% | Step 5 Preview |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Muse Spark 1.1 measured |
| IOI (Vals AI) | Not measured | 38.1% | Only Step 5 Preview measured |
| Terminal-Bench 2.1 (Vals AI) | 69.3% | Not measured | Only Muse Spark 1.1 measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 40.8% | Only Step 5 Preview measured |
| SkillsBench (Vals AI) | 59.2% | Not measured | Only Muse Spark 1.1 measured |
| SciCode | 58.8% | 58.9% | Step 5 Preview |
| LMArena Text: coding | 1498 | 1485 | Muse Spark 1.1 |
| LMArena Text: software and IT | 1498 | 1473 | Muse Spark 1.1 |
| LMArena WebDev: React | 1532 | 1583 | Step 5 Preview |
| LMArena WebDev: HTML | 1540 | 1556 | Step 5 Preview |
| LMArena WebDev: from an image | 1540 | 1550 | Step 5 Preview |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Muse Spark 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 33.7 | 43.7 | Step 5 Preview |
| Epoch Capabilities Index | 154.1 | Not measured | Only Muse Spark 1.1 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | Muse Spark 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| AA Agentic Index | 25.8 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: agents building web apps | 1207 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: agents building full-stack apps | 1199 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: agents building mobile apps | 1175 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: agents building Android apps | 1178 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: agents building Godot games | 1103 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: agents building games | 1183 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: HTML slides | 1195 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: PowerPoint slides | 1155 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: spreadsheets | 1042 | Not measured | Only Muse Spark 1.1 measured |
| LiveBench research | Not measured | 72.8% | Only Step 5 Preview measured |
| LiveBench browser | Not measured | 24.0% | Only Step 5 Preview measured |
| LiveBench long agentic | Not measured | 27.5% | Only Step 5 Preview measured |
| SREBench (Vals AI) | Not measured | 0.4% | Only Step 5 Preview measured |
| Finance Agent (Vals AI) | 57.2% | 50.7% | Muse Spark 1.1 |
| Tax Agent Bench (Vals AI) | Not measured | 27.3% | Only Step 5 Preview measured |
| Legal Research Bench (Vals AI) | 38.0% | 40.4% | Step 5 Preview |
| Excel Modeling Benchmark (Vals AI) | 56.4% | 57.1% | Step 5 Preview |
| BioMysteryBench (Vals AI) | Not measured | 67.4% | Only Step 5 Preview measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 2.9% | Only Step 5 Preview measured |
| Vals Science Index | Not measured | 29.6% | Only Step 5 Preview measured |
| Time Horizon Index (Vals AI) | 1.7% | Not measured | Only Muse Spark 1.1 measured |
| APEX-Agents | 31.8% | Not measured | Only Muse Spark 1.1 measured |
| Vending-Bench 2 | $6,520 | Not measured | Only Muse Spark 1.1 measured |
| Neither model has a result on the other 17 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index33
| Benchmark | Muse Spark 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| GPQA Diamond | 91.2% | Not measured | Only Muse Spark 1.1 measured |
| LiveBench reasoning | Not measured | 83.8% | Only Step 5 Preview measured |
| MysteryMechanism (Vals AI) | Not measured | 18.5% | Only Step 5 Preview measured |
| MMMU Pro (Vals AI) | 86.6% | Not measured | Only Muse Spark 1.1 measured |
| GPQA Diamond (Artificial Analysis run) | 89.8% | Not measured | Only Muse Spark 1.1 measured |
| Humanity's Last Exam (Artificial Analysis run) | 46.2% | 46.5% | Step 5 Preview |
| Chess puzzles | 34.0% | Not measured | Only Muse Spark 1.1 measured |
| LMArena Text: hard prompts | 1485 | 1461 | Muse Spark 1.1 |
| LMArena Text: expert | 1478 | 1485 | Step 5 Preview |
| LMArena Text: hard prompts in English | 1480 | 1454 | Muse Spark 1.1 |
| LMArena Vision: diagrams | 1305 | 1308 | Step 5 Preview |
| LMArena Vision: homework | 1287 | 1265 | Muse Spark 1.1 |
| Neither model has a result on the other 10 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index21
| Benchmark | Muse Spark 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| ProofBench | 39.0% | 42.0% | Step 5 Preview |
| LMArena Text: math | 1482 | 1458 | Muse Spark 1.1 |
| LMArena Text: mathematical work | 1487 | 1460 | Muse Spark 1.1 |
| 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 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| MMLU Pro | 88.7% | Not measured | Only Muse Spark 1.1 measured |
| LegalBench (Vals AI) | 85.0% | Not measured | Only Muse Spark 1.1 measured |
| CorpFin (Vals AI) | 71.3% | Not measured | Only Muse Spark 1.1 measured |
| TaxEval (Vals AI) | 79.7% | Not measured | Only Muse Spark 1.1 measured |
| MortgageTax (Vals AI) | 66.1% | Not measured | Only Muse Spark 1.1 measured |
| SimpleQA Verified | 57.8% | Not measured | Only Muse Spark 1.1 measured |
| LMArena Text: science | 1484 | 1454 | Muse Spark 1.1 |
| LMArena Text: medicine and healthcare | 1479 | 1439 | Muse Spark 1.1 |
| LMArena Text: legal and government | 1481 | 1437 | Muse Spark 1.1 |
| LMArena Text: business and finance | 1470 | 1435 | Muse Spark 1.1 |
| Neither model has a result on the other 8 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | Muse Spark 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| Design Arena: websites | 1270 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: UI components | 1289 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: game dev | 1269 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: data viz | 1268 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: 3D | 1260 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: all code categories | 1276 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: SVG | 1235 | Not measured | Only Muse Spark 1.1 measured |
| Design Arena: ASCII art | 1271 | Not measured | Only Muse Spark 1.1 measured |
| LiveBench design | Not measured | 76.9% | Only Step 5 Preview measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index181
| Benchmark | Muse Spark 1.1 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 63.5% | Only Step 5 Preview measured |
| Public Benefits Bench (Vals AI) | 61.3% | 58.1% | Muse Spark 1.1 |
| SAGE (Vals AI) | 45.6% | Not measured | Only Muse Spark 1.1 measured |
| MedScribe (Vals AI) | 88.9% | Not measured | Only Muse Spark 1.1 measured |
| Vals Multimodal Index | 66.7% | Not measured | Only Muse Spark 1.1 measured |
| Long context reasoning (AA-LCR) | 77.7% | 88.3% | Step 5 Preview |
| DTBench | 94.4% | Not measured | Only Muse Spark 1.1 measured |
| LMCA | 49.9% | Not measured | Only Muse Spark 1.1 measured |
| Surface Evolver Bench | 52.5% | Not measured | Only Muse Spark 1.1 measured |
| LMArena Text | 1478 | 1440 | Muse Spark 1.1 |
| LMArena Text: instruction following | 1457 | 1438 | Muse Spark 1.1 |
| LMArena Text: creative writing | 1435 | 1409 | Muse Spark 1.1 |
| LMArena Vision | 1293 | 1265 | Muse Spark 1.1 |
| LMArena Text: English | 1478 | 1447 | Muse Spark 1.1 |
| LMArena Text: non-English | 1471 | 1428 | Muse Spark 1.1 |
| LMArena Text: Chinese | 1515 | 1500 | Muse Spark 1.1 |
| LMArena Text: German | 1469 | Not measured | Only Muse Spark 1.1 measured |
| LMArena Text: Japanese | 1450 | 1383 | Muse Spark 1.1 |
| LMArena Text: Korean | 1459 | Not measured | Only Muse Spark 1.1 measured |
| LMArena Text: French | 1492 | 1438 | Muse Spark 1.1 |
| LMArena Text: Spanish | 1464 | 1441 | Muse Spark 1.1 |
| LMArena Text: Russian | 1482 | 1433 | Muse Spark 1.1 |
| LMArena Text: Polish | 1499 | Not measured | Only Muse Spark 1.1 measured |
| LMArena Text: multi-turn | 1484 | 1437 | Muse Spark 1.1 |
| LMArena Text: longer queries | 1462 | 1449 | Muse Spark 1.1 |
| LMArena Text: writing and language | 1448 | 1425 | Muse Spark 1.1 |
| LMArena Text: entertainment and media | 1438 | 1412 | Muse Spark 1.1 |
| LMArena Vision: English | 1292 | 1290 | Muse Spark 1.1 |
| LMArena Vision: Chinese | 1348 | Not measured | Only Muse Spark 1.1 measured |
| LMArena Vision: reading text | 1301 | 1282 | Muse Spark 1.1 |
| LMArena Vision: humor | 1288 | Not measured | Only Muse Spark 1.1 measured |
| LMArena Vision: creative writing | 1253 | Not measured | Only Muse Spark 1.1 measured |
| LMArena Document | 1465 | Not measured | Only Muse Spark 1.1 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 | Muse Spark 1.1 | Step 5 Preview | 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
Step 5 Preview costs less
Repository review
50K input + 3K output tokens
Step 5 Preview costs less
Agent loop
200K input + 10K output tokens
Step 5 Preview 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 1.1 | StepFun Step 5 Preview |
|---|---|---|
| Maker | Meta | StepFun |
| Weights | No public weights listed | Open weights |
| Released | July 16, 2026 | October 8, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $1.25 | $1.00 |
| Output $/Mtok | $4.25 | $2.70 |
| Coding index | 70.3 | 61.1 |
| Independent measurements behind it | 3 | 4 |
| Cost per solved task | $0.43 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark 1.1 better than Step 5 Preview for coding?
Pick Muse Spark 1.1 for coding: it scores 70.3 on the Vibe Coding Index against 61.1 for Step 5 Preview, though on 3 benchmarks against 4. Pick Step 5 Preview for output tokens 1.6x cheaper ($2.70 vs $4.25 per million) and work measured by LMArena WebDev or Code migration (Vals AI), where it leads.
Which is cheaper, Muse Spark 1.1 or Step 5 Preview?
Muse Spark 1.1 costs $1.25 per million input tokens and $4.25 per million output tokens; Step 5 Preview costs $1.00 and $2.70. Cost per solved task is known for Muse Spark 1.1 only.
Which has the bigger context window, Muse Spark 1.1 or Step 5 Preview?
Neither: both take 1.05M tokens.
How many benchmarks is the Muse Spark 1.1 vs Step 5 Preview comparison based on?
45 benchmarks have a result for both models as of October 22, 2026. Muse Spark 1.1's coding index rests on 3 independent benchmarks and Step 5 Preview's on 4. Where only one model has a result, the page says so instead of naming a winner.