Muse Spark Open vs o3 Pro
Updated October 21, 2026. 2 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Muse Spark Open scores 62.1 and o3 Pro 84.9 on the Vibe Coding Index, but no coding benchmark measured both, so the gap is directional, not a ranking.
Pick Muse Spark Open when output tokens cost 18.8x less, or when the context window is larger, 1.05M against 200K tokens.
- Shared results
- 2
- Muse Spark Open only
- 24
- o3 Pro only
- 9
- Like-for-like categories
- 2 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
No call
62.1 against 84.9, from different benchmarks with none in common.
Directional only
Intelligence
AA Intelligence Index
No call
Only o3 Pro has a AA Intelligence Index result, 21.9.
Directional only
Web design
Design Arena: websites
No call
Only Muse Spark Open has a Design Arena: websites result, 1311.
Directional only
Long documents
Listed context window
Muse Spark Open
Muse Spark Open takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Spark Open
Muse Spark Open $0.0034, o3 Pro $0.060 per turn.
List prices
At a glance
- Coding index
- Muse Spark Open 62.1 from 2 benchmarks, o3 Pro 84.9 from 1 benchmark.
- Widest category
- Intelligence, 9.7 points apart on average over 1 shared benchmark.
- Widest single gap
- Epoch Capabilities Index: Muse Spark Open 155.1 against o3 Pro 147.3, 9.7 points apart on a 0 to 100 scale.
- Output price
- Muse Spark Open $4.25 against o3 Pro $80.00 per million output tokens, 18.8x apart.
- Context window
- Muse Spark Open takes 1.05M tokens, o3 Pro 200K.
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 | o3 Pro | Ties |
|---|---|---|---|---|
| Intelligence | 1 | 0 | ||
| Reasoning | 1 | 0 | ||
| All shared boards | 2 | 0 |
CodingDirectional onlyFour of these boards feed the Vibe Coding Index11 boards, none shared
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 84.9% | Only o3 Pro measured |
| LiveBench coding | 73.6% | Not measured | Only Muse Spark Open measured |
| LMArena WebDev | 1528 | Not measured | Only Muse Spark Open measured |
| Terminal-Bench 4 (Vals AI) | 6.6% | Not measured | Only Muse Spark Open measured |
| Vibe Code Bench (Vals AI) | 76.2% | Not measured | Only Muse Spark Open measured |
| Code migration (Vals AI) | 21.2% | Not measured | Only Muse Spark Open measured |
| SciCode | 58.4% | Not measured | Only Muse Spark Open measured |
| WeirdML | Not measured | 58.2% | Only o3 Pro measured |
| ALE-Bench | 1590.1 | Not measured | Only Muse Spark Open measured |
| LMArena WebDev: React | 1529 | Not measured | Only Muse Spark Open measured |
| LMArena WebDev: HTML | 1495 | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 27 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 21.9 | Only o3 Pro measured |
| Epoch Capabilities Index | 155.1 | 147.3 | Muse Spark Open |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| LiveBench research | 80.3% | Not measured | Only Muse Spark Open measured |
| LiveBench browser | 36.0% | Not measured | Only Muse Spark Open measured |
| LiveBench long agentic | 18.9% | Not measured | Only Muse Spark Open measured |
| Finance Agent (Vals AI) | 61.3% | Not measured | Only Muse Spark Open measured |
| Tax Agent Bench (Vals AI) | 26.3% | Not measured | Only Muse Spark Open measured |
| Legal Research Bench (Vals AI) | 38.5% | Not measured | Only Muse Spark Open measured |
| Excel Modeling Benchmark (Vals AI) | 53.7% | Not measured | Only Muse Spark Open measured |
| APEX-Agents | 33.4% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 31 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| LiveBench reasoning | 73.7% | Not measured | Only Muse Spark Open measured |
| GPQA Diamond (Artificial Analysis run) | 89.0% | 84.5% | Muse Spark Open |
| Humanity's Last Exam (Artificial Analysis run) | 43.9% | Not measured | Only Muse Spark Open measured |
| ARC-AGI | Not measured | 59.3% | Only o3 Pro measured |
| ARC-AGI-2 | Not measured | 4.9% | Only o3 Pro measured |
| Neither model has a result on the other 16 boards here | |||
MathNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| Neither model has a result on 13 boards here | |||
KnowledgeNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| Neither model has a result on 17 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| Design Arena: websites | 1311 | Not measured | Only Muse Spark Open measured |
| Design Arena: game dev | 1290 | Not measured | Only Muse Spark Open measured |
| LiveBench design | 60.3% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 6 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Muse Spark Open | o3 Pro | Leader |
|---|---|---|---|
| LiveBench data analysis | 60.2% | Not measured | Only Muse Spark Open measured |
| Long context reasoning (AA-LCR) | 78.3% | Not measured | Only Muse Spark Open measured |
| DTBench | Not measured | 86.9% | Only o3 Pro measured |
| LMCA | Not measured | 38.5% | Only o3 Pro measured |
| Fiction.LiveBench | Not measured | 97.2% | Only o3 Pro measured |
| Creative writing (Lech Mazur) | Not measured | 84.4% | Only o3 Pro measured |
| Neither model has a result on the other 40 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | o3 Pro | 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 Open costs less
Repository review
50K input + 3K output tokens
Muse Spark Open costs less
Agent loop
200K input + 10K output tokens
Muse Spark Open 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 | OpenAI o3 Pro |
|---|---|---|
| Maker | Meta | OpenAI |
| Weights | Open weights | No public weights listed |
| Released | October 15, 2026 | June 10, 2025 |
| Context window | 1.05M | 200K |
| Input $/Mtok | $1.25 | $20.00 |
| Output $/Mtok | $4.25 | $80.00 |
| Coding index | 62.1 | 84.9 |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark Open better than o3 Pro for coding?
Muse Spark Open scores 62.1 and o3 Pro 84.9 on the Vibe Coding Index, but no coding benchmark measured both, so the gap is directional, not a ranking. Pick Muse Spark Open when output tokens cost 18.8x less, or when the context window is larger, 1.05M against 200K tokens.
Which is cheaper, Muse Spark Open or o3 Pro?
Muse Spark Open costs $1.25 per million input tokens and $4.25 per million output tokens; o3 Pro costs $20.00 and $80.00. Cost per solved task is known for neither of them.
Which has the bigger context window, Muse Spark Open or o3 Pro?
Muse Spark Open, with 1.05M tokens against 200K.
How many benchmarks is the Muse Spark Open vs o3 Pro comparison based on?
2 benchmarks have a result for both models as of October 21, 2026. Muse Spark Open's coding index rests on 2 independent benchmarks and o3 Pro's on 1. Where only one model has a result, the page says so instead of naming a winner.