GPT-5.6 Luna vs Muse Spark 1.1
Updated October 21, 2026. 85 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Pick GPT-5.6 Luna for coding: it scores 61.5 on the Vibe Coding Index against 48.9 for Muse Spark 1.1.
Pick Muse Spark 1.1 when what matters is LMArena WebDev or SciCode, where it leads.
- Shared results
- 85
- GPT-5.6 Luna only
- 31
- Muse Spark 1.1 only
- 11
- 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
GPT-5.6 Luna
GPT-5.6 Luna scores 61.5 against 48.9.
2 and 1 benchmarks behind the scores
Intelligence
AA Intelligence Index
GPT-5.6 Luna
GPT-5.6 Luna leads, 37.3 against 33.7.
Same board, both measured
Agentic work
AA Agentic Index
GPT-5.6 Luna
GPT-5.6 Luna leads, 42.1 against 25.8.
Same board, both measured
Reasoning
GPQA Diamond
GPT-5.6 Luna
GPT-5.6 Luna leads, 91.7% against 91.2%.
Same board, both measured
Knowledge
MMLU Pro
Muse Spark 1.1
Muse Spark 1.1 leads, 88.7% against 86.0%.
Same board, both measured
Web design
Design Arena: websites
Muse Spark 1.1
Muse Spark 1.1 leads, 1270 against 1256.
Same board, both measured
Long documents
Listed context window
GPT-5.6 Luna
GPT-5.6 Luna takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.6 Luna
GPT-5.6 Luna $0.0008, Muse Spark 1.1 $0.0034 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
GPT-5.6 Luna
GPT-5.6 Luna $0.04, Muse Spark 1.1 $0.43.
Published attempt cost and pass rate
At a glance
- Coding index
- GPT-5.6 Luna 61.5 from 2 benchmarks, Muse Spark 1.1 48.9 from 1 benchmark.
- Widest category
- Agentic work, 9.5 points apart on average over 6 shared benchmarks.
- Widest single gap
- ProofBench: GPT-5.6 Luna 60.0% against Muse Spark 1.1 39.0%, 21.0 points apart on a 0 to 100 scale.
- Output price
- GPT-5.6 Luna $1.20 against Muse Spark 1.1 $4.25 per million output tokens, 3.5x apart.
- Context window
- GPT-5.6 Luna takes 1.05M tokens, Muse Spark 1.1 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 | GPT-5.6 Luna | Bars | Muse Spark 1.1 | Ties |
|---|---|---|---|---|
| Coding | 6 | 7 | 1 tie | |
| Intelligence | 2 | 0 | ||
| Agentic work | 3 | 3 | ||
| Reasoning | 3 | 7 | ||
| Math | 1 | 2 | ||
| Knowledge | 1 | 9 | ||
| Web design | 0 | 8 | ||
| General | 4 | 28 | ||
| All shared boards | 20 | 64 | 1 tie |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index67
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| LiveBench coding | 73.6% | Not measured | Only GPT-5.6 Luna measured |
| LMArena WebDev | 1518 | 1542 | Muse Spark 1.1 |
| AA Coding Index | 71.4 | 71.3 | GPT-5.6 Luna |
| LiveCodeBench (Vals AI) | Not measured | 85.9% | Only Muse Spark 1.1 measured |
| SWE-bench Verified (Vals AI) | 93.0% | 82.0% | GPT-5.6 Luna |
| Terminal-Bench 4 (Vals AI) | 11.6% | Not measured | Only GPT-5.6 Luna measured |
| Vibe Code Bench (Vals AI) | 77.1% | 72.2% | GPT-5.6 Luna |
| Code migration (Vals AI) | 44.5% | 31.1% | GPT-5.6 Luna |
| ProgramBench (Vals AI) | 0.0% | 0.0% | Tie |
| IOI (Vals AI) | 61.8% | Not measured | Only GPT-5.6 Luna measured |
| Terminal-Bench 2.1 (Vals AI) | 79.0% | 69.3% | GPT-5.6 Luna |
| Vibe Code Bench 1-100 (Vals AI) | 22.6% | Not measured | Only GPT-5.6 Luna measured |
| SkillsBench (Vals AI) | 60.5% | 59.2% | GPT-5.6 Luna |
| CyberBench (Vals AI) | 73.6% | Not measured | Only GPT-5.6 Luna measured |
| SciCode | 53.6% | 58.8% | Muse Spark 1.1 |
| FrontierCode | 39.8% | Not measured | Only GPT-5.6 Luna measured |
| WeirdML | 60.9% | Not measured | Only GPT-5.6 Luna measured |
| ALE-Bench | 1667.4 | Not measured | Only GPT-5.6 Luna measured |
| LMArena Text: coding | 1466 | 1498 | Muse Spark 1.1 |
| LMArena Text: software and IT | 1463 | 1498 | Muse Spark 1.1 |
| LMArena WebDev: React | 1508 | 1532 | Muse Spark 1.1 |
| LMArena WebDev: HTML | 1520 | 1540 | Muse Spark 1.1 |
| LMArena WebDev: from an image | 1517 | 1540 | Muse Spark 1.1 |
| Neither model has a result on the other 15 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| AA Intelligence Index | 37.3 | 33.7 | GPT-5.6 Luna |
| Epoch Capabilities Index | 156.5 | 154.1 | GPT-5.6 Luna |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index33
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| AA Agentic Index | 42.1 | 25.8 | GPT-5.6 Luna |
| Design Arena: agents building web apps | Not measured | 1207 | Only Muse Spark 1.1 measured |
| Design Arena: agents building full-stack apps | Not measured | 1199 | Only Muse Spark 1.1 measured |
| Design Arena: agents building mobile apps | Not measured | 1177 | Only Muse Spark 1.1 measured |
| Design Arena: agents building Android apps | Not measured | 1184 | Only Muse Spark 1.1 measured |
| Design Arena: agents building Godot games | Not measured | 1103 | Only Muse Spark 1.1 measured |
| Design Arena: agents building games | Not measured | 1183 | Only Muse Spark 1.1 measured |
| Design Arena: HTML slides | Not measured | 1194 | Only Muse Spark 1.1 measured |
| Design Arena: PowerPoint slides | Not measured | 1156 | Only Muse Spark 1.1 measured |
| Design Arena: spreadsheets | Not measured | 974 | Only Muse Spark 1.1 measured |
| LiveBench research | 51.0% | Not measured | Only GPT-5.6 Luna measured |
| LiveBench browser | 68.0% | Not measured | Only GPT-5.6 Luna measured |
| LiveBench long agentic | 30.4% | Not measured | Only GPT-5.6 Luna measured |
| SREBench (Vals AI) | 1.5% | Not measured | Only GPT-5.6 Luna measured |
| Finance Agent (Vals AI) | 55.0% | 57.2% | Muse Spark 1.1 |
| Tax Agent Bench (Vals AI) | 24.8% | Not measured | Only GPT-5.6 Luna measured |
| Legal Research Bench (Vals AI) | 36.5% | 38.0% | Muse Spark 1.1 |
| Excel Modeling Benchmark (Vals AI) | 67.1% | 56.4% | GPT-5.6 Luna |
| BioMysteryBench (Vals AI) | 61.5% | Not measured | Only GPT-5.6 Luna measured |
| Terminal-Bench-Science (Vals AI) | 0.0% | Not measured | Only GPT-5.6 Luna measured |
| Vals Science Index | 25.3% | Not measured | Only GPT-5.6 Luna measured |
| Time Horizon Index (Vals AI) | Not measured | 1.7% | Only Muse Spark 1.1 measured |
| APEX-Agents | 43.0% | 31.8% | GPT-5.6 Luna |
| BALROG | 45.6% | Not measured | Only GPT-5.6 Luna measured |
| Vending-Bench 2 | $4,095 | $6,520 | Muse Spark 1.1 |
| Neither model has a result on the other 14 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index37
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| GPQA Diamond | 91.7% | 91.2% | GPT-5.6 Luna |
| LiveBench reasoning | 85.6% | Not measured | Only GPT-5.6 Luna measured |
| MysteryMechanism (Vals AI) | 14.4% | Not measured | Only GPT-5.6 Luna measured |
| MMMU Pro (Vals AI) | 85.0% | 86.6% | Muse Spark 1.1 |
| GPQA Diamond (Artificial Analysis run) | 91.1% | 89.8% | GPT-5.6 Luna |
| Humanity's Last Exam (Artificial Analysis run) | 39.5% | 46.2% | Muse Spark 1.1 |
| GPQA Diamond (Epoch AI run) | 91.6% | Not measured | Only GPT-5.6 Luna measured |
| ARC-AGI | 88.0% | Not measured | Only GPT-5.6 Luna measured |
| ARC-AGI-2 | 59.5% | Not measured | Only GPT-5.6 Luna measured |
| SimpleBench | 46.8% | Not measured | Only GPT-5.6 Luna measured |
| Chess puzzles | 43.0% | 34.0% | GPT-5.6 Luna |
| Mystery game puzzles | 21.0% | Not measured | Only GPT-5.6 Luna measured |
| LMArena Text: hard prompts | 1451 | 1485 | Muse Spark 1.1 |
| LMArena Text: expert | 1478 | 1478 | Muse Spark 1.1 |
| LMArena Text: hard prompts in English | 1460 | 1480 | Muse Spark 1.1 |
| LMArena Vision: diagrams | 1273 | 1305 | Muse Spark 1.1 |
| LMArena Vision: homework | 1282 | 1287 | Muse Spark 1.1 |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 98.3% | Not measured | Only GPT-5.6 Luna measured |
| FrontierMath, tiers 1 to 3 | 82.1% | Not measured | Only GPT-5.6 Luna measured |
| FrontierMath, tier 4 | 61.0% | Not measured | Only GPT-5.6 Luna measured |
| ProofBench | 60.0% | 39.0% | GPT-5.6 Luna |
| LMArena Text: math | 1459 | 1482 | Muse Spark 1.1 |
| LMArena Text: mathematical work | 1470 | 1487 | Muse Spark 1.1 |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index19
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| MMLU Pro | 86.0% | 88.7% | Muse Spark 1.1 |
| LegalBench (Vals AI) | 84.0% | 85.0% | Muse Spark 1.1 |
| CorpFin (Vals AI) | 64.2% | 71.3% | Muse Spark 1.1 |
| TaxEval (Vals AI) | 76.2% | 79.7% | Muse Spark 1.1 |
| MortgageTax (Vals AI) | 67.3% | 66.1% | GPT-5.6 Luna |
| MedCode (Vals AI) | 42.4% | Not measured | Only GPT-5.6 Luna measured |
| SimpleQA Verified | 41.0% | 57.8% | Muse Spark 1.1 |
| LMArena Text: science | 1433 | 1484 | Muse Spark 1.1 |
| LMArena Text: medicine and healthcare | 1399 | 1479 | Muse Spark 1.1 |
| LMArena Text: legal and government | 1446 | 1481 | Muse Spark 1.1 |
| LMArena Text: business and finance | 1439 | 1470 | Muse Spark 1.1 |
| Neither model has a result on the other 6 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| Design Arena: websites | 1256 | 1270 | Muse Spark 1.1 |
| Design Arena: UI components | 1250 | 1290 | Muse Spark 1.1 |
| Design Arena: game dev | 1196 | 1269 | Muse Spark 1.1 |
| Design Arena: data viz | 1212 | 1268 | Muse Spark 1.1 |
| Design Arena: 3D | 1121 | 1260 | Muse Spark 1.1 |
| Design Arena: all code categories | 1231 | 1276 | Muse Spark 1.1 |
| Design Arena: SVG | 1193 | 1234 | Muse Spark 1.1 |
| Design Arena: ASCII art | 1144 | 1270 | Muse Spark 1.1 |
| LiveBench design | 76.0% | Not measured | Only GPT-5.6 Luna measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index428
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | Leader |
|---|---|---|---|
| LiveBench data analysis | 78.0% | Not measured | Only GPT-5.6 Luna measured |
| Public Benefits Bench (Vals AI) | 61.2% | 61.3% | Muse Spark 1.1 |
| SAGE (Vals AI) | 44.2% | 45.6% | Muse Spark 1.1 |
| MedScribe (Vals AI) | 84.4% | 88.9% | Muse Spark 1.1 |
| Vals Multimodal Index | 69.1% | 66.7% | GPT-5.6 Luna |
| Long context reasoning (AA-LCR) | 83.7% | 77.7% | GPT-5.6 Luna |
| DTBench | 89.1% | 94.4% | Muse Spark 1.1 |
| LMCA | 48.5% | 49.9% | Muse Spark 1.1 |
| Surface Evolver Bench | 61.9% | 52.5% | GPT-5.6 Luna |
| Furniture assembly | 42.5% | Not measured | Only GPT-5.6 Luna measured |
| LMArena Text | 1431 | 1478 | Muse Spark 1.1 |
| LMArena Text: instruction following | 1437 | 1457 | Muse Spark 1.1 |
| LMArena Text: creative writing | 1396 | 1435 | Muse Spark 1.1 |
| LMArena Vision | 1257 | 1293 | Muse Spark 1.1 |
| LMArena Text: English | 1441 | 1478 | Muse Spark 1.1 |
| LMArena Text: non-English | 1417 | 1471 | Muse Spark 1.1 |
| LMArena Text: Chinese | 1470 | 1515 | Muse Spark 1.1 |
| LMArena Text: German | 1455 | 1469 | Muse Spark 1.1 |
| LMArena Text: Japanese | 1415 | 1450 | Muse Spark 1.1 |
| LMArena Text: Korean | 1415 | 1459 | Muse Spark 1.1 |
| LMArena Text: French | 1458 | 1492 | Muse Spark 1.1 |
| LMArena Text: Spanish | 1446 | 1464 | Muse Spark 1.1 |
| LMArena Text: Russian | 1427 | 1482 | Muse Spark 1.1 |
| LMArena Text: Polish | 1405 | 1499 | Muse Spark 1.1 |
| LMArena Text: multi-turn | 1434 | 1484 | Muse Spark 1.1 |
| LMArena Text: longer queries | 1436 | 1462 | Muse Spark 1.1 |
| LMArena Text: writing and language | 1419 | 1448 | Muse Spark 1.1 |
| LMArena Text: entertainment and media | 1402 | 1438 | Muse Spark 1.1 |
| LMArena Vision: English | 1263 | 1292 | Muse Spark 1.1 |
| LMArena Vision: Chinese | 1294 | 1348 | Muse Spark 1.1 |
| LMArena Vision: reading text | 1264 | 1301 | Muse Spark 1.1 |
| LMArena Vision: humor | 1190 | 1288 | Muse Spark 1.1 |
| LMArena Vision: creative writing | 1257 | 1253 | GPT-5.6 Luna |
| LMArena Document | 1457 | 1465 | Muse Spark 1.1 |
| Neither model has a result on the other 12 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.6 Luna | Muse Spark 1.1 | 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
GPT-5.6 Luna costs less
Repository review
50K input + 3K output tokens
GPT-5.6 Luna costs less
Agent loop
200K input + 10K output tokens
GPT-5.6 Luna 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 | OpenAI GPT-5.6 Luna | Meta Muse Spark 1.1 |
|---|---|---|
| Maker | OpenAI | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | July 9, 2026 | July 16, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.20 | $1.25 |
| Output $/Mtok | $1.20 | $4.25 |
| Coding index | 61.5 | 48.9 |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | $0.04 | $0.43 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.6 Luna better than Muse Spark 1.1 for coding?
Pick GPT-5.6 Luna for coding: it scores 61.5 on the Vibe Coding Index against 48.9 for Muse Spark 1.1. Pick Muse Spark 1.1 when what matters is LMArena WebDev or SciCode, where it leads.
Which is cheaper, GPT-5.6 Luna or Muse Spark 1.1?
GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens; Muse Spark 1.1 costs $1.25 and $4.25. Per solved SWE-bench Verified task, GPT-5.6 Luna costs $0.04 and Muse Spark 1.1 $0.43.
Which has the bigger context window, GPT-5.6 Luna or Muse Spark 1.1?
GPT-5.6 Luna, with 1.05M tokens against 1.05M.
How many benchmarks is the GPT-5.6 Luna vs Muse Spark 1.1 comparison based on?
85 benchmarks have a result for both models as of October 21, 2026. GPT-5.6 Luna's coding index rests on 2 independent benchmarks and Muse Spark 1.1's on 1. Where only one model has a result, the page says so instead of naming a winner.