GPT-5.5 vs Muse Spark 1.1
Updated October 21, 2026. 95 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-5.5 for coding: it scores 67.8 on the Vibe Coding Index against 48.9 for Muse Spark 1.1.
Pick Muse Spark 1.1 when output tokens cost 7.1x less, or when a solved task costs $0.43 against $1.65.
- Shared results
- 95
- GPT-5.5 only
- 37
- Muse Spark 1.1 only
- 1
- 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-5.5
GPT-5.5 scores 67.8 against 48.9.
2 and 1 benchmarks behind the scores
Intelligence
AA Intelligence Index
GPT-5.5
GPT-5.5 leads, 38.4 against 33.7.
Same board, both measured
Agentic work
AA Agentic Index
GPT-5.5
GPT-5.5 leads, 36.4 against 25.8.
Same board, both measured
Reasoning
GPQA Diamond
GPT-5.5
GPT-5.5 leads, 93.2% against 91.2%.
Same board, both measured
Knowledge
MMLU Pro
Muse Spark 1.1
Muse Spark 1.1 leads, 88.7% against 88.1%.
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-5.5
GPT-5.5 takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Spark 1.1
GPT-5.5 $0.020, Muse Spark 1.1 $0.0034 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Muse Spark 1.1
GPT-5.5 $1.65, Muse Spark 1.1 $0.43.
Published attempt cost and pass rate
At a glance
- Coding index
- GPT-5.5 67.8 from 2 benchmarks, Muse Spark 1.1 48.9 from 1 benchmark.
- Widest category
- Agentic work, 8.3 points apart on average over 15 shared benchmarks.
- Widest single gap
- Surface Evolver Bench: GPT-5.5 88.1% against Muse Spark 1.1 52.5%, 35.6 points apart on a 0 to 100 scale.
- Output price
- GPT-5.5 $30.00 against Muse Spark 1.1 $4.25 per million output tokens, 7.1x apart.
- Context window
- GPT-5.5 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-5.5 | Bars | Muse Spark 1.1 | Ties |
|---|---|---|---|---|
| Coding | 7 | 8 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 7 | 8 | ||
| Reasoning | 9 | 1 | ||
| Math | 3 | 0 | ||
| Knowledge | 6 | 4 | ||
| Web design | 1 | 6 | 1 tie | |
| General | 23 | 9 | ||
| All shared boards | 58 | 36 | 1 tie |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index78
| Benchmark | GPT-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| LiveBench coding | 85.1% | Not measured | Only GPT-5.5 measured |
| LMArena WebDev | 1513 | 1542 | Muse Spark 1.1 |
| AA Coding Index | 74.9 | 71.3 | GPT-5.5 |
| LiveCodeBench (Vals AI) | 85.3% | 85.9% | Muse Spark 1.1 |
| SWE-bench Verified (Vals AI) | 82.6% | 82.0% | GPT-5.5 |
| Vibe Code Bench (Vals AI) | 69.8% | 72.2% | Muse Spark 1.1 |
| Code migration (Vals AI) | 45.2% | 31.1% | GPT-5.5 |
| ProgramBench (Vals AI) | 0.5% | 0.0% | GPT-5.5 |
| Terminal-Bench 2.1 (Vals AI) | 76.4% | 69.3% | GPT-5.5 |
| SkillsBench (Vals AI) | 62.5% | 59.2% | GPT-5.5 |
| SciCode | 56.1% | 58.8% | Muse Spark 1.1 |
| Terminal-Bench Hard (Artificial Analysis run) | 60.6% | Not measured | Only GPT-5.5 measured |
| Terminal-Bench | 84.7% | Not measured | Only GPT-5.5 measured |
| FrontierCode | 43.0% | Not measured | Only GPT-5.5 measured |
| GSO-Bench | 40.2% | Not measured | Only GPT-5.5 measured |
| WeirdML | 84.9% | Not measured | Only GPT-5.5 measured |
| MirrorCode | 10.0% | Not measured | Only GPT-5.5 measured |
| ALE-Bench | 1943.0 | Not measured | Only GPT-5.5 measured |
| LMArena Text: coding | 1494 | 1498 | Muse Spark 1.1 |
| LMArena Text: software and IT | 1493 | 1498 | Muse Spark 1.1 |
| LMArena WebDev: React | 1506 | 1532 | Muse Spark 1.1 |
| LMArena WebDev: HTML | 1543 | 1540 | GPT-5.5 |
| LMArena WebDev: from an image | 1532 | 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-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| AA Intelligence Index | 38.4 | 33.7 | GPT-5.5 |
| Epoch Capabilities Index | 159.7 | 154.1 | GPT-5.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index78
| Benchmark | GPT-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| AA Agentic Index | 36.4 | 25.8 | GPT-5.5 |
| Design Arena: agents building web apps | 1117 | 1207 | Muse Spark 1.1 |
| Design Arena: agents building full-stack apps | 1089 | 1199 | Muse Spark 1.1 |
| Design Arena: agents building mobile apps | 1143 | 1177 | Muse Spark 1.1 |
| Design Arena: agents building Android apps | 1169 | 1184 | Muse Spark 1.1 |
| Design Arena: agents building Godot games | 1173 | 1103 | GPT-5.5 |
| Design Arena: agents building games | 1179 | 1183 | Muse Spark 1.1 |
| Design Arena: HTML slides | 1067 | 1194 | Muse Spark 1.1 |
| Design Arena: PowerPoint slides | 1108 | 1156 | Muse Spark 1.1 |
| Design Arena: spreadsheets | Not measured | 974 | Only Muse Spark 1.1 measured |
| LiveBench research | 61.6% | Not measured | Only GPT-5.5 measured |
| LiveBench browser | 48.0% | Not measured | Only GPT-5.5 measured |
| LiveBench long agentic | 44.6% | Not measured | Only GPT-5.5 measured |
| SREBench (Vals AI) | 3.8% | Not measured | Only GPT-5.5 measured |
| Finance Agent (Vals AI) | 51.8% | 57.2% | Muse Spark 1.1 |
| Tax Agent Bench (Vals AI) | 21.8% | Not measured | Only GPT-5.5 measured |
| Legal Research Bench (Vals AI) | 40.4% | 38.0% | GPT-5.5 |
| Excel Modeling Benchmark (Vals AI) | 64.5% | 56.4% | GPT-5.5 |
| Time Horizon Index (Vals AI) | 8.3% | 1.7% | GPT-5.5 |
| τ²-Bench Telecom | 93.9% | Not measured | Only GPT-5.5 measured |
| APEX-Agents | 55.1% | 31.8% | GPT-5.5 |
| Remote Labor Index | 6.3% | Not measured | Only GPT-5.5 measured |
| OSWorld 2.0 | 13.0% | Not measured | Only GPT-5.5 measured |
| DeepResearch Bench | 54.0% | Not measured | Only GPT-5.5 measured |
| PostTrainBench | 27.2% | Not measured | Only GPT-5.5 measured |
| Vending-Bench 2 | $7,524 | $6,520 | GPT-5.5 |
| Neither model has a result on the other 13 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index91
| Benchmark | GPT-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| GPQA Diamond | 93.2% | 91.2% | GPT-5.5 |
| LiveBench reasoning | 89.7% | Not measured | Only GPT-5.5 measured |
| MMMU Pro (Vals AI) | 88.3% | 86.6% | GPT-5.5 |
| GPQA Diamond (Artificial Analysis run) | 93.5% | 89.8% | GPT-5.5 |
| Humanity's Last Exam (Artificial Analysis run) | 45.8% | 46.2% | Muse Spark 1.1 |
| GPQA Diamond (Epoch AI run) | 90.7% | Not measured | Only GPT-5.5 measured |
| ARC-AGI | 95.0% | Not measured | Only GPT-5.5 measured |
| ARC-AGI-2 | 85.0% | Not measured | Only GPT-5.5 measured |
| SimpleBench | 69.0% | Not measured | Only GPT-5.5 measured |
| Chess puzzles | 63.0% | 34.0% | GPT-5.5 |
| Mystery game puzzles | 56.0% | Not measured | Only GPT-5.5 measured |
| EBR-bench | 34.3% | Not measured | Only GPT-5.5 measured |
| LMArena Text: hard prompts | 1489 | 1485 | GPT-5.5 |
| LMArena Text: expert | 1507 | 1478 | GPT-5.5 |
| LMArena Text: hard prompts in English | 1483 | 1480 | GPT-5.5 |
| LMArena Vision: diagrams | 1325 | 1305 | GPT-5.5 |
| LMArena Vision: homework | 1332 | 1287 | GPT-5.5 |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | GPT-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 84.4% | Not measured | Only GPT-5.5 measured |
| FrontierMath, tiers 1 to 3 | 85.3% | Not measured | Only GPT-5.5 measured |
| FrontierMath, tier 4 | 72.5% | Not measured | Only GPT-5.5 measured |
| ProofBench | 50.0% | 39.0% | GPT-5.5 |
| LMArena Text: math | 1487 | 1482 | GPT-5.5 |
| LMArena Text: mathematical work | 1496 | 1487 | GPT-5.5 |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index64
| Benchmark | GPT-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| MMLU Pro | 88.1% | 88.7% | Muse Spark 1.1 |
| LegalBench (Vals AI) | 86.5% | 85.0% | GPT-5.5 |
| CaseLaw (Vals AI) | 66.2% | Not measured | Only GPT-5.5 measured |
| CorpFin (Vals AI) | 68.4% | 71.3% | Muse Spark 1.1 |
| TaxEval (Vals AI) | 75.0% | 79.7% | Muse Spark 1.1 |
| MortgageTax (Vals AI) | 68.8% | 66.1% | GPT-5.5 |
| MedCode (Vals AI) | 49.1% | Not measured | Only GPT-5.5 measured |
| SimpleQA Verified | 63.0% | 57.8% | GPT-5.5 |
| LMArena Text: science | 1485 | 1484 | GPT-5.5 |
| LMArena Text: medicine and healthcare | 1465 | 1479 | Muse Spark 1.1 |
| LMArena Text: legal and government | 1491 | 1481 | GPT-5.5 |
| LMArena Text: business and finance | 1478 | 1470 | GPT-5.5 |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index16
| Benchmark | GPT-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| Design Arena: websites | 1256 | 1270 | Muse Spark 1.1 |
| Design Arena: UI components | 1260 | 1290 | Muse Spark 1.1 |
| Design Arena: game dev | 1294 | 1269 | GPT-5.5 |
| Design Arena: data viz | 1265 | 1268 | Muse Spark 1.1 |
| Design Arena: 3D | 1198 | 1260 | Muse Spark 1.1 |
| Design Arena: all code categories | 1260 | 1276 | Muse Spark 1.1 |
| Design Arena: SVG | 1234 | 1234 | Tie |
| Design Arena: ASCII art | 1254 | 1270 | Muse Spark 1.1 |
| LiveBench design | 70.3% | Not measured | Only GPT-5.5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index239
| Benchmark | GPT-5.5 | Muse Spark 1.1 | Leader |
|---|---|---|---|
| LiveBench data analysis | 81.6% | Not measured | Only GPT-5.5 measured |
| Public Benefits Bench (Vals AI) | 60.9% | 61.3% | Muse Spark 1.1 |
| SAGE (Vals AI) | 51.5% | 45.6% | GPT-5.5 |
| MedScribe (Vals AI) | 86.9% | 88.9% | Muse Spark 1.1 |
| Vals Multimodal Index | 68.1% | 66.7% | GPT-5.5 |
| IFBench | 75.9% | Not measured | Only GPT-5.5 measured |
| Long context reasoning (AA-LCR) | 84.3% | 77.7% | GPT-5.5 |
| DTBench | 96.0% | 94.4% | GPT-5.5 |
| LMCA | 54.3% | 49.9% | GPT-5.5 |
| Surface Evolver Bench | 88.1% | 52.5% | GPT-5.5 |
| Furniture assembly | 44.2% | Not measured | Only GPT-5.5 measured |
| ExploitBench | 47.4% | Not measured | Only GPT-5.5 measured |
| CL-bench Life | 22.2% | Not measured | Only GPT-5.5 measured |
| LMArena Text | 1471 | 1478 | Muse Spark 1.1 |
| LMArena Text: instruction following | 1478 | 1457 | GPT-5.5 |
| LMArena Text: creative writing | 1455 | 1435 | GPT-5.5 |
| LMArena Vision | 1297 | 1293 | GPT-5.5 |
| LMArena Text: English | 1470 | 1478 | Muse Spark 1.1 |
| LMArena Text: non-English | 1467 | 1471 | Muse Spark 1.1 |
| LMArena Text: Chinese | 1534 | 1515 | GPT-5.5 |
| LMArena Text: German | 1480 | 1469 | GPT-5.5 |
| LMArena Text: Japanese | 1499 | 1450 | GPT-5.5 |
| LMArena Text: Korean | 1460 | 1459 | GPT-5.5 |
| LMArena Text: French | 1485 | 1492 | Muse Spark 1.1 |
| LMArena Text: Spanish | 1468 | 1464 | GPT-5.5 |
| LMArena Text: Russian | 1473 | 1482 | Muse Spark 1.1 |
| LMArena Text: Polish | 1465 | 1499 | Muse Spark 1.1 |
| LMArena Text: multi-turn | 1476 | 1484 | Muse Spark 1.1 |
| LMArena Text: longer queries | 1484 | 1462 | GPT-5.5 |
| LMArena Text: writing and language | 1466 | 1448 | GPT-5.5 |
| LMArena Text: entertainment and media | 1449 | 1438 | GPT-5.5 |
| LMArena Vision: English | 1292 | 1292 | GPT-5.5 |
| LMArena Vision: Chinese | 1360 | 1348 | GPT-5.5 |
| LMArena Vision: reading text | 1306 | 1301 | GPT-5.5 |
| LMArena Vision: humor | 1293 | 1288 | GPT-5.5 |
| LMArena Vision: recognizing things | 1231 | Not measured | Only GPT-5.5 measured |
| LMArena Vision: creative writing | 1301 | 1253 | GPT-5.5 |
| LMArena Document | 1486 | 1465 | GPT-5.5 |
| Neither model has a result on the other 8 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.5 | 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
Muse Spark 1.1 costs less
Repository review
50K input + 3K output tokens
Muse Spark 1.1 costs less
Agent loop
200K input + 10K output tokens
Muse Spark 1.1 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-5.5 | Meta Muse Spark 1.1 |
|---|---|---|
| Maker | OpenAI | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | April 24, 2026 | July 16, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $5.00 | $1.25 |
| Output $/Mtok | $30.00 | $4.25 |
| Coding index | 67.8 | 48.9 |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | $1.65 | $0.43 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.5 better than Muse Spark 1.1 for coding?
Pick GPT-5.5 for coding: it scores 67.8 on the Vibe Coding Index against 48.9 for Muse Spark 1.1. Pick Muse Spark 1.1 when output tokens cost 7.1x less, or when a solved task costs $0.43 against $1.65.
Which is cheaper, GPT-5.5 or Muse Spark 1.1?
GPT-5.5 costs $5.00 per million input tokens and $30.00 per million output tokens; Muse Spark 1.1 costs $1.25 and $4.25. Per solved SWE-bench Verified task, GPT-5.5 costs $1.65 and Muse Spark 1.1 $0.43.
Which has the bigger context window, GPT-5.5 or Muse Spark 1.1?
GPT-5.5, with 1.05M tokens against 1.05M.
How many benchmarks is the GPT-5.5 vs Muse Spark 1.1 comparison based on?
95 benchmarks have a result for both models as of October 21, 2026. GPT-5.5'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.