Muse Spark Open vs Inkling
Muse Spark Open leads Inkling on coding, 47.4 to 31.5 on the Vibe Coding Index, at about the same output price ($4.25 vs $4.05 per million). Updated October 22, 2026; 28 benchmarks have a result for both.
Muse Spark Open or Inkling: which to pick
Pick Muse Spark Open for coding: it scores 47.4 on the Vibe Coding Index against 31.5 for Inkling, though on 4 benchmarks against 6.
Pick Inkling for output tokens 1.0x cheaper ($4.05 vs $4.25 per million) and work measured by APEX-Agents or LiveBench reasoning, where it leads.
- Shared results
- 28
- Muse Spark Open only
- 0
- Inkling only
- 74
- Like-for-like categories
- 6 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 Open
Muse Spark Open scores 47.4 against 31.5.
4 and 6 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Inkling has a AA Intelligence Index result, 25.0.
Directional only
Agentic work
AA Agentic Index
No call
Only Inkling has a AA Agentic Index result, 22.5.
Directional only
Reasoning
GPQA Diamond
No call
Only Inkling has a GPQA Diamond result, 87.1%.
Directional only
Knowledge
MMLU Pro
No call
Only Inkling has a MMLU Pro result, 86.3%.
Directional only
Web design
Design Arena: websites
Muse Spark Open
Muse Spark Open leads, 1310 against 1224.
Same board, both measured
General
Vals Index
Muse Spark Open
Muse Spark Open leads, 48.6% against 29.0%.
Same board, both measured
Long documents
Listed context window
Muse Spark Open
Muse Spark Open takes 1.05M tokens against 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Inkling
Muse Spark Open $0.0034, Inkling $0.0030 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Inkling has the number, $0.76.
Directional only
At a glance
- Coding index
- Muse Spark Open 47.4 from 4 benchmarks, Inkling 31.5 from 6 benchmarks.
- Widest category
- Coding, 18.9 points apart on average over 9 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Muse Spark Open 76.2% against Inkling 19.2%, 57.0 points apart on a 0 to 100 scale.
- Output price
- Muse Spark Open $4.25 against Inkling $4.05 per million output tokens, 1.0x apart.
- Context window
- Muse Spark Open takes 1.05M tokens, Inkling 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 Open | Bars | Inkling | Ties |
|---|---|---|---|---|
| Coding | 9 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 8 | 1 | ||
| Reasoning | 2 | 1 | ||
| Web design | 3 | 0 | ||
| General | 2 | 1 | ||
| All shared boards | 25 | 3 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index90
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| LiveBench coding | 73.6% | 64.0% | Muse Spark Open |
| LMArena WebDev | 1528 | 1414 | Muse Spark Open |
| AA Coding Index | Not measured | 52.1 | Only Inkling measured |
| LiveCodeBench (Vals AI) | Not measured | 85.5% | Only Inkling measured |
| SWE-bench Verified (Vals AI) | Not measured | 77.6% | Only Inkling measured |
| Terminal-Bench 4 (Vals AI) | 6.6% | 0.5% | Muse Spark Open |
| Vibe Code Bench (Vals AI) | 76.2% | 19.2% | Muse Spark Open |
| Code migration (Vals AI) | 21.2% | 11.8% | Muse Spark Open |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Inkling measured |
| IOI (Vals AI) | Not measured | 14.9% | Only Inkling measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 47.6% | Only Inkling measured |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 7.3% | Only Inkling measured |
| SkillsBench (Vals AI) | Not measured | 26.1% | Only Inkling measured |
| CyberBench (Vals AI) | Not measured | 66.8% | Only Inkling measured |
| SciCode | 58.4% | 47.0% | Muse Spark Open |
| FrontierCode | Not measured | 14.0% | Only Inkling measured |
| FrontierSWE | Not measured | 4.1% | Only Inkling measured |
| WeirdML | Not measured | 32.3% | Only Inkling measured |
| ALE-Bench | 1590.1 | 946.0 | Muse Spark Open |
| LMArena Text: coding | Not measured | 1466 | Only Inkling measured |
| LMArena Text: software and IT | Not measured | 1465 | Only Inkling measured |
| LMArena WebDev: React | 1529 | 1404 | Muse Spark Open |
| LMArena WebDev: HTML | 1495 | 1399 | Muse Spark Open |
| Neither model has a result on the other 16 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 25.0 | Only Inkling measured |
| Epoch Capabilities Index | 155.1 | 148.4 | Muse Spark Open |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index81
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 22.5 | Only Inkling measured |
| Design Arena: agents building web apps | Not measured | 1196 | Only Inkling measured |
| LiveBench research | 80.3% | 59.9% | Muse Spark Open |
| LiveBench browser | 36.0% | 16.0% | Muse Spark Open |
| LiveBench long agentic | 18.9% | 14.1% | Muse Spark Open |
| SREBench (Vals AI) | Not measured | 0.0% | Only Inkling measured |
| Finance Agent (Vals AI) | 61.3% | 46.6% | Muse Spark Open |
| Tax Agent Bench (Vals AI) | 26.3% | 15.3% | Muse Spark Open |
| Legal Research Bench (Vals AI) | 38.5% | 28.4% | Muse Spark Open |
| Harvey's Legal Agent Benchmark (Vals AI) | 25.0% | 3.8% | Muse Spark Open |
| Excel Modeling Benchmark (Vals AI) | 53.7% | 38.4% | Muse Spark Open |
| APEX-Agents | 33.4% | 33.8% | Inkling |
| Neither model has a result on the other 29 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index21
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 87.1% | Only Inkling measured |
| LiveBench reasoning | 73.7% | 78.3% | Inkling |
| MMMU Pro (Vals AI) | Not measured | 78.5% | Only Inkling measured |
| GPQA Diamond (Artificial Analysis run) | 89.0% | 87.2% | Muse Spark Open |
| Humanity's Last Exam (Artificial Analysis run) | 43.9% | 31.9% | Muse Spark Open |
| GPQA Diamond (Epoch AI run) | Not measured | 88.3% | Only Inkling measured |
| ARC-AGI | Not measured | 79.5% | Only Inkling measured |
| ARC-AGI-2 | Not measured | 36.5% | Only Inkling measured |
| SimpleBench | Not measured | 50.0% | Only Inkling measured |
| Chess puzzles | Not measured | 21.0% | Only Inkling measured |
| LMArena Text: hard prompts | Not measured | 1451 | Only Inkling measured |
| LMArena Text: expert | Not measured | 1466 | Only Inkling measured |
| LMArena Text: hard prompts in English | Not measured | 1448 | Only Inkling measured |
| Neither model has a result on the other 9 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| OTIS Mock AIME | Not measured | 88.9% | Only Inkling measured |
| FrontierMath, tiers 1 to 3 | Not measured | 33.3% | Only Inkling measured |
| FrontierMath, tier 4 | Not measured | 4.9% | Only Inkling measured |
| ProofBench | Not measured | 0.0% | Only Inkling measured |
| LMArena Text: math | Not measured | 1479 | Only Inkling measured |
| LMArena Text: mathematical work | Not measured | 1460 | Only Inkling measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index11 boards, none shared
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 86.3% | Only Inkling measured |
| LegalBench (Vals AI) | Not measured | 83.0% | Only Inkling measured |
| CorpFin (Vals AI) | Not measured | 68.6% | Only Inkling measured |
| TaxEval (Vals AI) | Not measured | 75.3% | Only Inkling measured |
| MortgageTax (Vals AI) | Not measured | 64.0% | Only Inkling measured |
| MedCode (Vals AI) | Not measured | 41.2% | Only Inkling measured |
| SimpleQA Verified | Not measured | 40.3% | Only Inkling measured |
| LMArena Text: science | Not measured | 1455 | Only Inkling measured |
| LMArena Text: medicine and healthcare | Not measured | 1447 | Only Inkling measured |
| LMArena Text: legal and government | Not measured | 1448 | Only Inkling measured |
| LMArena Text: business and finance | Not measured | 1438 | Only Inkling measured |
| Neither model has a result on the other 7 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| Design Arena: websites | 1310 | 1224 | Muse Spark Open |
| Design Arena: UI components | Not measured | 1198 | Only Inkling measured |
| Design Arena: game dev | 1282 | 1165 | Muse Spark Open |
| Design Arena: data viz | Not measured | 1156 | Only Inkling measured |
| Design Arena: 3D | Not measured | 1160 | Only Inkling measured |
| Design Arena: all code categories | Not measured | 1205 | Only Inkling measured |
| Design Arena: SVG | Not measured | 1108 | Only Inkling measured |
| Design Arena: ASCII art | Not measured | 1089 | Only Inkling measured |
| LiveBench design | 60.3% | 58.3% | Muse Spark Open |
GeneralLike-for-likePublic boards, shown as published, kept out of the index21
| Benchmark | Muse Spark Open | Inkling | Leader |
|---|---|---|---|
| Vals Index | 48.6% | 29.0% | Muse Spark Open |
| LiveBench data analysis | 60.2% | 72.8% | Inkling |
| Public Benefits Bench (Vals AI) | Not measured | 58.5% | Only Inkling measured |
| SAGE (Vals AI) | Not measured | 36.5% | Only Inkling measured |
| MedScribe (Vals AI) | Not measured | 85.4% | Only Inkling measured |
| Vals Multimodal Index | Not measured | 49.4% | Only Inkling measured |
| Long context reasoning (AA-LCR) | 78.3% | 77.3% | Muse Spark Open |
| DTBench | Not measured | 87.5% | Only Inkling measured |
| LMCA | Not measured | 37.6% | Only Inkling measured |
| LMArena Text | Not measured | 1442 | Only Inkling measured |
| LMArena Text: instruction following | Not measured | 1425 | Only Inkling measured |
| LMArena Text: creative writing | Not measured | 1390 | Only Inkling measured |
| LMArena Text: English | Not measured | 1442 | Only Inkling measured |
| LMArena Text: non-English | Not measured | 1434 | Only Inkling measured |
| LMArena Text: Chinese | Not measured | 1493 | Only Inkling measured |
| LMArena Text: German | Not measured | 1445 | Only Inkling measured |
| LMArena Text: Japanese | Not measured | 1429 | Only Inkling measured |
| LMArena Text: Korean | Not measured | 1403 | Only Inkling measured |
| LMArena Text: French | Not measured | 1455 | Only Inkling measured |
| LMArena Text: Spanish | Not measured | 1449 | Only Inkling measured |
| LMArena Text: Russian | Not measured | 1430 | Only Inkling measured |
| LMArena Text: Polish | Not measured | 1450 | Only Inkling measured |
| LMArena Text: multi-turn | Not measured | 1437 | Only Inkling measured |
| LMArena Text: longer queries | Not measured | 1435 | Only Inkling measured |
| LMArena Text: writing and language | Not measured | 1404 | Only Inkling measured |
| LMArena Text: entertainment and media | Not measured | 1394 | Only Inkling measured |
| Neither model has a result on the other 20 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | Inkling | 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
Inkling costs less
Repository review
50K input + 3K output tokens
Inkling costs less
Agent loop
200K input + 10K output tokens
Inkling 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 Open | Thinking Machines Inkling |
|---|---|---|
| Maker | Meta | Thinking Machines |
| Weights | Open weights | Open weights |
| Released | October 15, 2026 | July 17, 2026 |
| Context window | 1.05M | 524K |
| Input $/Mtok | $1.25 | $0.975 |
| Output $/Mtok | $4.25 | $4.05 |
| Coding index | 47.4 | 31.5 |
| Independent measurements behind it | 4 | 6 |
| Cost per solved task | Not computable | $0.76 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark Open better than Inkling for coding?
Pick Muse Spark Open for coding: it scores 47.4 on the Vibe Coding Index against 31.5 for Inkling, though on 4 benchmarks against 6. Pick Inkling for output tokens 1.0x cheaper ($4.05 vs $4.25 per million) and work measured by APEX-Agents or LiveBench reasoning, where it leads.
Which is cheaper, Muse Spark Open or Inkling?
Muse Spark Open costs $1.25 per million input tokens and $4.25 per million output tokens; Inkling costs $0.975 and $4.05. Cost per solved task is known for Inkling only.
Which has the bigger context window, Muse Spark Open or Inkling?
Muse Spark Open, with 1.05M tokens against 524K.
How many benchmarks is the Muse Spark Open vs Inkling comparison based on?
28 benchmarks have a result for both models as of October 22, 2026. Muse Spark Open's coding index rests on 4 independent benchmarks and Inkling's on 6. Where only one model has a result, the page says so instead of naming a winner.