Kimi K3.1 Pro vs Muse Spark 1.2
Kimi K3.1 Pro leads Muse Spark 1.2 on coding, 82.2 to 50.9 on the Vibe Coding Index, and Muse Spark 1.2 costs 2.4x less per output token ($4.25 vs $10.00 per million). Updated October 29, 2026; 20 benchmarks have a result for both.
Kimi K3.1 Pro or Muse Spark 1.2: which to pick
Pick Kimi K3.1 Pro for coding: it scores 82.2 on the Vibe Coding Index against 50.9 for Muse Spark 1.2.
Pick Muse Spark 1.2 for output tokens 2.4x cheaper ($4.25 vs $10.00 per million) and work measured by Tax Agent Bench (Vals AI) or Legal Research Bench (Vals AI), where it leads.
- Shared results
- 20
- Kimi K3.1 Pro only
- 15
- Muse Spark 1.2 only
- 71
- 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
Kimi K3.1 Pro
Kimi K3.1 Pro scores 82.2 against 50.9.
4 benchmarks behind each score
Intelligence
AA Intelligence Index
No call
Only Kimi K3.1 Pro has a AA Intelligence Index result, 46.0.
Directional only
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
Kimi K3.1 Pro
Kimi K3.1 Pro leads, 1325 against 1311.
Same board, both measured
General
Vals Index
No call
Only Kimi K3.1 Pro has a Vals Index result, 62.5%.
Directional only
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Spark 1.2
Kimi K3.1 Pro $0.0070, Muse Spark 1.2 $0.0034 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
- Kimi K3.1 Pro 82.2 from 4 benchmarks, Muse Spark 1.2 50.9 from 4 benchmarks.
- Widest category
- Math, 48.0 points apart on average over 1 shared benchmark.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Kimi K3.1 Pro 63.6% against Muse Spark 1.2 6.1%, 76.8 points apart on a 0 to 100 scale.
- Output price
- Kimi K3.1 Pro $10.00 against Muse Spark 1.2 $4.25 per million output tokens, 2.4x 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 | Kimi K3.1 Pro | Bars | Muse Spark 1.2 | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Agentic work | 1 | 2 | ||
| Reasoning | 1 | 0 | ||
| Math | 1 | 0 | ||
| Web design | 6 | 1 | ||
| General | 1 | 0 | ||
| All shared boards | 17 | 3 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| LiveBench coding | 81.8% | Not measured | Only Kimi K3.1 Pro measured |
| LMArena WebDev | 1695 | 1534 | Kimi K3.1 Pro |
| AA Coding Index | Not measured | 72.2 | Only Muse Spark 1.2 measured |
| SWE-bench Verified (Vals AI) | Not measured | 86.6% | Only Muse Spark 1.2 measured |
| Terminal-Bench 4 (Vals AI) | 63.6% | 6.1% | Kimi K3.1 Pro |
| Vibe Code Bench (Vals AI) | 84.9% | 79.1% | Kimi K3.1 Pro |
| Code migration (Vals AI) | Not measured | 29.9% | Only Muse Spark 1.2 measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Muse Spark 1.2 measured |
| IOI (Vals AI) | 81.9% | 21.8% | Kimi K3.1 Pro |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 69.7% | Only Muse Spark 1.2 measured |
| SkillsBench (Vals AI) | Not measured | 53.0% | Only Muse Spark 1.2 measured |
| CyberBench (Vals AI) | Not measured | 69.5% | Only Muse Spark 1.2 measured |
| SciCode | 60.8% | 57.4% | Kimi K3.1 Pro |
| FrontierSWE | Not measured | 12.0% | Only Muse Spark 1.2 measured |
| WeirdML | Not measured | 60.3% | Only Muse Spark 1.2 measured |
| ALE-Bench | 1932.8 | Not measured | Only Kimi K3.1 Pro measured |
| LMArena Text: coding | Not measured | 1506 | Only Muse Spark 1.2 measured |
| LMArena Text: software and IT | Not measured | 1508 | Only Muse Spark 1.2 measured |
| LMArena WebDev: React | 1701 | 1526 | Kimi K3.1 Pro |
| LMArena WebDev: HTML | 1706 | 1543 | Kimi K3.1 Pro |
| Neither model has a result on the other 23 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| AA Intelligence Index | 46.0 | Not measured | Only Kimi K3.1 Pro measured |
| Epoch Capabilities Index | Not measured | 155.1 | Only Muse Spark 1.2 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 43.2 | Only Muse Spark 1.2 measured |
| Design Arena: agents building web apps | Not measured | 1223 | Only Muse Spark 1.2 measured |
| Design Arena: agents building full-stack apps | Not measured | 1210 | Only Muse Spark 1.2 measured |
| Design Arena: agents building mobile apps | Not measured | 1184 | Only Muse Spark 1.2 measured |
| Design Arena: agents building Android apps | Not measured | 1220 | Only Muse Spark 1.2 measured |
| Design Arena: agents building games | Not measured | 1142 | Only Muse Spark 1.2 measured |
| Design Arena: HTML slides | Not measured | 1031 | Only Muse Spark 1.2 measured |
| Design Arena: PowerPoint slides | Not measured | 1149 | Only Muse Spark 1.2 measured |
| Design Arena: spreadsheets | Not measured | 1059 | Only Muse Spark 1.2 measured |
| LiveBench research | 77.9% | Not measured | Only Kimi K3.1 Pro measured |
| LiveBench browser | 75.9% | Not measured | Only Kimi K3.1 Pro measured |
| LiveBench long agentic | 39.1% | Not measured | Only Kimi K3.1 Pro measured |
| SREBench (Vals AI) | Not measured | 0.0% | Only Muse Spark 1.2 measured |
| Finance Agent (Vals AI) | Not measured | 60.6% | Only Muse Spark 1.2 measured |
| Tax Agent Bench (Vals AI) | 24.9% | 32.8% | Muse Spark 1.2 |
| Legal Research Bench (Vals AI) | 37.5% | 43.8% | Muse Spark 1.2 |
| Harvey's Legal Agent Benchmark (Vals AI) | 11.7% | Not measured | Only Kimi K3.1 Pro measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 57.0% | Only Muse Spark 1.2 measured |
| BioMysteryBench (Vals AI) | 75.6% | 64.8% | Kimi K3.1 Pro |
| Terminal-Bench-Science (Vals AI) | 31.4% | Not measured | Only Kimi K3.1 Pro measured |
| Vals Science Index | 44.4% | Not measured | Only Kimi K3.1 Pro measured |
| APEX-Agents | Not measured | 45.4% | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 20 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| LiveBench reasoning | 91.1% | Not measured | Only Kimi K3.1 Pro measured |
| MysteryMechanism (Vals AI) | 26.1% | Not measured | Only Kimi K3.1 Pro measured |
| MMMU Pro (Vals AI) | Not measured | 86.1% | Only Muse Spark 1.2 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 90.4% | Only Muse Spark 1.2 measured |
| Humanity's Last Exam (Artificial Analysis run) | 52.5% | 45.5% | Kimi K3.1 Pro |
| SimpleBench | Not measured | 74.5% | Only Muse Spark 1.2 measured |
| Chess puzzles | Not measured | 27.0% | Only Muse Spark 1.2 measured |
| LMArena Text: hard prompts | Not measured | 1492 | Only Muse Spark 1.2 measured |
| LMArena Text: expert | Not measured | 1477 | Only Muse Spark 1.2 measured |
| LMArena Text: hard prompts in English | Not measured | 1491 | Only Muse Spark 1.2 measured |
| LMArena Vision: diagrams | Not measured | 1317 | 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 index10
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| ProofBench | 91.0% | 43.0% | Kimi K3.1 Pro |
| LMArena Text: math | Not measured | 1485 | Only Muse Spark 1.2 measured |
| LMArena Text: mathematical work | Not measured | 1488 | Only Muse Spark 1.2 measured |
| MathArena | 59.6% | Not measured | Only Kimi K3.1 Pro measured |
| Neither model has a result on the other 10 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index11 boards, none shared
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 88.3% | Only Muse Spark 1.2 measured |
| LegalBench (Vals AI) | Not measured | 85.3% | Only Muse Spark 1.2 measured |
| CorpFin (Vals AI) | Not measured | 70.9% | Only Muse Spark 1.2 measured |
| TaxEval (Vals AI) | Not measured | 80.4% | Only Muse Spark 1.2 measured |
| MortgageTax (Vals AI) | Not measured | 65.4% | Only Muse Spark 1.2 measured |
| MedCode (Vals AI) | Not measured | 49.4% | Only Muse Spark 1.2 measured |
| SimpleQA Verified | Not measured | 60.3% | Only Muse Spark 1.2 measured |
| LMArena Text: science | Not measured | 1499 | Only Muse Spark 1.2 measured |
| LMArena Text: medicine and healthcare | Not measured | 1494 | Only Muse Spark 1.2 measured |
| LMArena Text: legal and government | Not measured | 1509 | Only Muse Spark 1.2 measured |
| LMArena Text: business and finance | Not measured | 1484 | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 9 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index61
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| Design Arena: websites | 1325 | 1311 | Kimi K3.1 Pro |
| Design Arena: UI components | 1400 | 1296 | Kimi K3.1 Pro |
| Design Arena: game dev | 1410 | 1300 | Kimi K3.1 Pro |
| Design Arena: data viz | 1300 | 1333 | Muse Spark 1.2 |
| Design Arena: 3D | 1451 | 1299 | Kimi K3.1 Pro |
| Design Arena: all code categories | 1354 | 1311 | Kimi K3.1 Pro |
| Design Arena: SVG | 1328 | 1280 | Kimi K3.1 Pro |
| Design Arena: ASCII art | Not measured | 1279 | Only Muse Spark 1.2 measured |
| LiveBench design | 77.8% | Not measured | Only Kimi K3.1 Pro measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | Leader |
|---|---|---|---|
| Vals Index | 62.5% | Not measured | Only Kimi K3.1 Pro measured |
| LiveBench data analysis | 79.1% | Not measured | Only Kimi K3.1 Pro measured |
| Public Benefits Bench (Vals AI) | Not measured | 68.5% | Only Muse Spark 1.2 measured |
| MedScribe (Vals AI) | Not measured | 90.1% | Only Muse Spark 1.2 measured |
| Vals Multimodal Index | Not measured | 69.8% | Only Muse Spark 1.2 measured |
| Long context reasoning (AA-LCR) | 86.3% | 79.0% | Kimi K3.1 Pro |
| DTBench | Not measured | 94.7% | Only Muse Spark 1.2 measured |
| LMCA | Not measured | 48.4% | Only Muse Spark 1.2 measured |
| LMArena Text | Not measured | 1483 | Only Muse Spark 1.2 measured |
| LMArena Text: instruction following | Not measured | 1465 | Only Muse Spark 1.2 measured |
| LMArena Text: creative writing | Not measured | 1437 | Only Muse Spark 1.2 measured |
| LMArena Vision | Not measured | 1304 | Only Muse Spark 1.2 measured |
| LMArena Text: English | Not measured | 1484 | Only Muse Spark 1.2 measured |
| LMArena Text: non-English | Not measured | 1475 | Only Muse Spark 1.2 measured |
| LMArena Text: Chinese | Not measured | 1510 | Only Muse Spark 1.2 measured |
| LMArena Text: German | Not measured | 1492 | Only Muse Spark 1.2 measured |
| LMArena Text: Japanese | Not measured | 1470 | Only Muse Spark 1.2 measured |
| LMArena Text: Korean | Not measured | 1454 | Only Muse Spark 1.2 measured |
| LMArena Text: French | Not measured | 1500 | Only Muse Spark 1.2 measured |
| LMArena Text: Spanish | Not measured | 1491 | Only Muse Spark 1.2 measured |
| LMArena Text: Russian | Not measured | 1481 | Only Muse Spark 1.2 measured |
| LMArena Text: multi-turn | Not measured | 1496 | Only Muse Spark 1.2 measured |
| LMArena Text: longer queries | Not measured | 1474 | Only Muse Spark 1.2 measured |
| LMArena Text: writing and language | Not measured | 1451 | Only Muse Spark 1.2 measured |
| LMArena Text: entertainment and media | Not measured | 1442 | Only Muse Spark 1.2 measured |
| LMArena Vision: English | Not measured | 1291 | Only Muse Spark 1.2 measured |
| LMArena Vision: reading text | Not measured | 1313 | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 21 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Kimi K3.1 Pro | Muse Spark 1.2 | 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
Muse Spark 1.2 costs less
Repository review
50K input + 3K output tokens
Muse Spark 1.2 costs less
Agent loop
200K input + 10K output tokens
Muse Spark 1.2 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 | MoonshotAI Kimi K3.1 Pro | Meta Muse Spark 1.2 |
|---|---|---|
| Maker | Moonshot AI | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | October 23, 2026 | August 5, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $2.00 | $1.25 |
| Output $/Mtok | $10.00 | $4.25 |
| Coding index | 82.2 | 50.9 |
| Independent measurements behind it | 4 | 4 |
| Cost per solved task | Not computable | $0.64 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Kimi K3.1 Pro better than Muse Spark 1.2 for coding?
Pick Kimi K3.1 Pro for coding: it scores 82.2 on the Vibe Coding Index against 50.9 for Muse Spark 1.2. Pick Muse Spark 1.2 for output tokens 2.4x cheaper ($4.25 vs $10.00 per million) and work measured by Tax Agent Bench (Vals AI) or Legal Research Bench (Vals AI), where it leads.
Which is cheaper, Kimi K3.1 Pro or Muse Spark 1.2?
Kimi K3.1 Pro costs $2.00 per million input tokens and $10.00 per million output tokens; Muse Spark 1.2 costs $1.25 and $4.25. Cost per solved task is known for Muse Spark 1.2 only.
Which has the bigger context window, Kimi K3.1 Pro or Muse Spark 1.2?
Neither: both take 1.05M tokens.
How many benchmarks is the Kimi K3.1 Pro vs Muse Spark 1.2 comparison based on?
20 benchmarks have a result for both models as of October 29, 2026. Kimi K3.1 Pro's coding index rests on 4 independent benchmarks and Muse Spark 1.2's on 4. Where only one model has a result, the page says so instead of naming a winner.