GPT-5.5 Pro vs Muse Spark 1.3
Muse Spark 1.3 costs 42.4x less per output token than GPT-5.5 Pro ($4.25 vs $180.00 per million). Updated October 22, 2026; 6 benchmarks have a result for both.
GPT-5.5 Pro or Muse Spark 1.3: which to pick
Only Muse Spark 1.3 has a coding score, 57.4 on the Vibe Coding Index; GPT-5.5 Pro has none, so the two cannot be ranked on coding.
Pick GPT-5.5 Pro for a larger context window (1.05M against 1.05M tokens) and work measured by Epoch Capabilities Index or Chess puzzles, where it leads.
- Shared results
- 6
- GPT-5.5 Pro only
- 3
- Muse Spark 1.3 only
- 86
- Like-for-like categories
- 4 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
No call
Only Muse Spark 1.3 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
No call
Only Muse Spark 1.3 has a AA Intelligence Index result, 48.1.
Directional only
Agentic work
AA Agentic Index
No call
Only Muse Spark 1.3 has a AA Agentic Index result, 55.5.
Directional only
Web design
Design Arena: websites
No call
Only Muse Spark 1.3 has a Design Arena: websites result, 1356.
Directional only
Long documents
Listed context window
GPT-5.5 Pro
GPT-5.5 Pro takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Spark 1.3
GPT-5.5 Pro $0.120, Muse Spark 1.3 $0.0034 per turn.
List prices
At a glance
- Coding index
- GPT-5.5 Pro not benchmarked, Muse Spark 1.3 57.4 from 4 benchmarks.
- Widest category
- Reasoning, 25.0 points apart on average over 1 shared benchmark.
- Widest single gap
- FrontierMath, tier 4: GPT-5.5 Pro 78.0% against Muse Spark 1.3 46.3%, 31.7 points apart on a 0 to 100 scale.
- Output price
- GPT-5.5 Pro $180.00 against Muse Spark 1.3 $4.25 per million output tokens, 42.4x apart.
- Context window
- GPT-5.5 Pro takes 1.05M tokens, Muse Spark 1.3 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 Pro | Bars | Muse Spark 1.3 | Ties |
|---|---|---|---|---|
| Intelligence | 1 | 0 | ||
| Reasoning | 1 | 0 | ||
| Math | 2 | 0 | ||
| General | 1 | 1 | ||
| All shared boards | 5 | 1 |
CodingDirectional onlySix of these boards feed the Vibe Coding Index18 boards, none shared
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 90.2% | Only Muse Spark 1.3 measured |
| LMArena WebDev | Not measured | 1659 | Only Muse Spark 1.3 measured |
| AA Coding Index | Not measured | 75.8 | Only Muse Spark 1.3 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 10.6% | Only Muse Spark 1.3 measured |
| Vibe Code Bench (Vals AI) | Not measured | 82.9% | Only Muse Spark 1.3 measured |
| Code migration (Vals AI) | Not measured | 27.6% | Only Muse Spark 1.3 measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Muse Spark 1.3 measured |
| IOI (Vals AI) | Not measured | 43.9% | Only Muse Spark 1.3 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 72.3% | Only Muse Spark 1.3 measured |
| CyberBench (Vals AI) | Not measured | 69.4% | Only Muse Spark 1.3 measured |
| SciCode | Not measured | 59.7% | Only Muse Spark 1.3 measured |
| FrontierSWE | Not measured | 25.8% | Only Muse Spark 1.3 measured |
| ALE-Bench | Not measured | 1688.3 | Only Muse Spark 1.3 measured |
| LMArena Text: coding | Not measured | 1510 | Only Muse Spark 1.3 measured |
| LMArena Text: software and IT | Not measured | 1511 | Only Muse Spark 1.3 measured |
| LMArena WebDev: React | Not measured | 1672 | Only Muse Spark 1.3 measured |
| LMArena WebDev: HTML | Not measured | 1653 | Only Muse Spark 1.3 measured |
| LMArena WebDev: from an image | Not measured | 1640 | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 21 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 48.1 | Only Muse Spark 1.3 measured |
| Epoch Capabilities Index | 162.9 | 157.2 | GPT-5.5 Pro |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index16 boards, none shared
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 55.5 | Only Muse Spark 1.3 measured |
| Design Arena: agents building web apps | Not measured | 1297 | Only Muse Spark 1.3 measured |
| Design Arena: agents building full-stack apps | Not measured | 1295 | Only Muse Spark 1.3 measured |
| Design Arena: agents building mobile apps | Not measured | 1218 | Only Muse Spark 1.3 measured |
| Design Arena: agents building Godot games | Not measured | 1241 | Only Muse Spark 1.3 measured |
| Design Arena: PowerPoint slides | Not measured | 1219 | Only Muse Spark 1.3 measured |
| Design Arena: spreadsheets | Not measured | 1062 | Only Muse Spark 1.3 measured |
| LiveBench research | Not measured | 68.6% | Only Muse Spark 1.3 measured |
| LiveBench browser | Not measured | 80.0% | Only Muse Spark 1.3 measured |
| LiveBench long agentic | Not measured | 40.4% | Only Muse Spark 1.3 measured |
| Finance Agent (Vals AI) | Not measured | 58.9% | Only Muse Spark 1.3 measured |
| Tax Agent Bench (Vals AI) | Not measured | 36.0% | Only Muse Spark 1.3 measured |
| Legal Research Bench (Vals AI) | Not measured | 40.9% | Only Muse Spark 1.3 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 62.7% | Only Muse Spark 1.3 measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 4.3% | Only Muse Spark 1.3 measured |
| APEX-Agents | Not measured | 58.6% | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 25 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| LiveBench reasoning | Not measured | 89.7% | Only Muse Spark 1.3 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 94.1% | Only Muse Spark 1.3 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 48.7% | Only Muse Spark 1.3 measured |
| ARC-AGI | 96.5% | Not measured | Only GPT-5.5 Pro measured |
| ARC-AGI-2 | 84.6% | Not measured | Only GPT-5.5 Pro measured |
| SimpleBench | 76.9% | Not measured | Only GPT-5.5 Pro measured |
| Chess puzzles | 62.0% | 37.0% | GPT-5.5 Pro |
| Mystery game puzzles | Not measured | 25.0% | Only Muse Spark 1.3 measured |
| LMArena Text: hard prompts | Not measured | 1503 | Only Muse Spark 1.3 measured |
| LMArena Text: expert | Not measured | 1519 | Only Muse Spark 1.3 measured |
| LMArena Text: hard prompts in English | Not measured | 1500 | Only Muse Spark 1.3 measured |
| LMArena Vision: diagrams | Not measured | 1330 | Only Muse Spark 1.3 measured |
| LMArena Vision: homework | Not measured | 1296 | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 9 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| OTIS Mock AIME | Not measured | 99.2% | Only Muse Spark 1.3 measured |
| FrontierMath, tiers 1 to 3 | 87.7% | 74.4% | GPT-5.5 Pro |
| FrontierMath, tier 4 | 78.0% | 46.3% | GPT-5.5 Pro |
| ProofBench | Not measured | 58.0% | Only Muse Spark 1.3 measured |
| LMArena Text: math | Not measured | 1497 | Only Muse Spark 1.3 measured |
| LMArena Text: mathematical work | Not measured | 1491 | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index4 boards, none shared
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| LMArena Text: science | Not measured | 1507 | Only Muse Spark 1.3 measured |
| LMArena Text: medicine and healthcare | Not measured | 1493 | Only Muse Spark 1.3 measured |
| LMArena Text: legal and government | Not measured | 1499 | Only Muse Spark 1.3 measured |
| LMArena Text: business and finance | Not measured | 1490 | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 14 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1356 | Only Muse Spark 1.3 measured |
| Design Arena: UI components | Not measured | 1349 | Only Muse Spark 1.3 measured |
| Design Arena: game dev | Not measured | 1328 | Only Muse Spark 1.3 measured |
| Design Arena: data viz | Not measured | 1343 | Only Muse Spark 1.3 measured |
| Design Arena: 3D | Not measured | 1358 | Only Muse Spark 1.3 measured |
| Design Arena: all code categories | Not measured | 1352 | Only Muse Spark 1.3 measured |
| Design Arena: SVG | Not measured | 1301 | Only Muse Spark 1.3 measured |
| Design Arena: ASCII art | Not measured | 1278 | Only Muse Spark 1.3 measured |
| LiveBench design | Not measured | 74.8% | Only Muse Spark 1.3 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 79.6% | Only Muse Spark 1.3 measured |
| Long context reasoning (AA-LCR) | Not measured | 83.0% | Only Muse Spark 1.3 measured |
| DTBench | 96.0% | 96.5% | Muse Spark 1.3 |
| LMCA | 53.9% | 53.9% | GPT-5.5 Pro |
| LMArena Text | Not measured | 1490 | Only Muse Spark 1.3 measured |
| LMArena Text: instruction following | Not measured | 1479 | Only Muse Spark 1.3 measured |
| LMArena Text: creative writing | Not measured | 1462 | Only Muse Spark 1.3 measured |
| LMArena Vision | Not measured | 1308 | Only Muse Spark 1.3 measured |
| LMArena Text: English | Not measured | 1495 | Only Muse Spark 1.3 measured |
| LMArena Text: non-English | Not measured | 1481 | Only Muse Spark 1.3 measured |
| LMArena Text: Chinese | Not measured | 1532 | Only Muse Spark 1.3 measured |
| LMArena Text: German | Not measured | 1513 | Only Muse Spark 1.3 measured |
| LMArena Text: Japanese | Not measured | 1470 | Only Muse Spark 1.3 measured |
| LMArena Text: Korean | Not measured | 1490 | Only Muse Spark 1.3 measured |
| LMArena Text: French | Not measured | 1511 | Only Muse Spark 1.3 measured |
| LMArena Text: Spanish | Not measured | 1496 | Only Muse Spark 1.3 measured |
| LMArena Text: Russian | Not measured | 1491 | Only Muse Spark 1.3 measured |
| LMArena Text: Polish | Not measured | 1490 | Only Muse Spark 1.3 measured |
| LMArena Text: multi-turn | Not measured | 1487 | Only Muse Spark 1.3 measured |
| LMArena Text: longer queries | Not measured | 1488 | Only Muse Spark 1.3 measured |
| LMArena Text: writing and language | Not measured | 1470 | Only Muse Spark 1.3 measured |
| LMArena Text: entertainment and media | Not measured | 1457 | Only Muse Spark 1.3 measured |
| LMArena Vision: English | Not measured | 1298 | Only Muse Spark 1.3 measured |
| LMArena Vision: Chinese | Not measured | 1384 | Only Muse Spark 1.3 measured |
| LMArena Vision: reading text | Not measured | 1319 | Only Muse Spark 1.3 measured |
| LMArena Vision: humor | Not measured | 1293 | Only Muse Spark 1.3 measured |
| LMArena Vision: creative writing | Not measured | 1296 | Only Muse Spark 1.3 measured |
| Neither model has a result on the other 19 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 | 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 1.3 costs less
Repository review
50K input + 3K output tokens
Muse Spark 1.3 costs less
Agent loop
200K input + 10K output tokens
Muse Spark 1.3 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 Pro | Meta Muse Spark 1.3 |
|---|---|---|
| Maker | OpenAI | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | April 24, 2026 | September 2, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $30.00 | $1.25 |
| Output $/Mtok | $180.00 | $4.25 |
| Coding index | Not benchmarked | 57.4 |
| Independent measurements behind it | 0 | 4 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.5 Pro better than Muse Spark 1.3 for coding?
Only Muse Spark 1.3 has a coding score, 57.4 on the Vibe Coding Index; GPT-5.5 Pro has none, so the two cannot be ranked on coding. Pick GPT-5.5 Pro for a larger context window (1.05M against 1.05M tokens) and work measured by Epoch Capabilities Index or Chess puzzles, where it leads.
Which is cheaper, GPT-5.5 Pro or Muse Spark 1.3?
GPT-5.5 Pro costs $30.00 per million input tokens and $180.00 per million output tokens; Muse Spark 1.3 costs $1.25 and $4.25. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-5.5 Pro or Muse Spark 1.3?
GPT-5.5 Pro, with 1.05M tokens against 1.05M.
How many benchmarks is the GPT-5.5 Pro vs Muse Spark 1.3 comparison based on?
6 benchmarks have a result for both models as of October 22, 2026. GPT-5.5 Pro's coding index rests on 0 independent benchmarks and Muse Spark 1.3's on 4. Where only one model has a result, the page says so instead of naming a winner.