Muse Spark Open vs o3 Mini
Updated October 21, 2026. 5 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Pick Muse Spark Open for coding: it scores 62.1 on the Vibe Coding Index against 52.1 for o3 Mini.
o3 Mini is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
- Shared results
- 5
- Muse Spark Open only
- 21
- o3 Mini only
- 65
- Like-for-like categories
- 4 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
Muse Spark Open
Muse Spark Open scores 62.1 against 52.1.
2 benchmarks behind each score
Intelligence
AA Intelligence Index
No call
Only o3 Mini has a AA Intelligence Index result, 12.5.
Directional only
Reasoning
GPQA Diamond
No call
Only o3 Mini has a GPQA Diamond result, 75.5%.
Directional only
Math
AIME
No call
Only o3 Mini has a AIME result, 86.5%.
Directional only
Knowledge
MMLU Pro
No call
Only o3 Mini has a MMLU Pro result, 78.7%.
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
o3 Mini
Muse Spark Open $0.0034, o3 Mini $0.0033 per turn.
List prices
At a glance
- Coding index
- Muse Spark Open 62.1 from 2 benchmarks, o3 Mini 52.1 from 2 benchmarks.
- Widest category
- General, 35.3 points apart on average over 1 shared benchmark.
- Widest single gap
- Long context reasoning (AA-LCR): Muse Spark Open 78.3% against o3 Mini 43.0%, 35.3 points apart on a 0 to 100 scale.
- Output price
- Muse Spark Open $4.25 against o3 Mini $4.40 per million output tokens, 1.0x apart.
- Context window
- Muse Spark Open takes 1.05M tokens, o3 Mini 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 Mini | Ties |
|---|---|---|---|---|
| Coding | 1 | 0 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 2 | 0 | ||
| General | 1 | 0 | ||
| All shared boards | 5 | 0 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index10
| Benchmark | Muse Spark Open | o3 Mini | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 60.4% | Only o3 Mini measured |
| SWE-bench Verified | Not measured | 42.4% | Only o3 Mini measured |
| SWE-bench Lite | Not measured | 32.3% | Only o3 Mini measured |
| LiveBench coding | 73.6% | Not measured | Only Muse Spark Open measured |
| LMArena WebDev | 1528 | Not measured | Only Muse Spark Open measured |
| LiveCodeBench (Vals AI) | Not measured | 71.5% | Only o3 Mini 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 |
| LiveCodeBench (Artificial Analysis run) | Not measured | 73.4% | Only o3 Mini measured |
| SciCode | 58.4% | 42.8% | Muse Spark Open |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 6.8% | Only o3 Mini measured |
| GSO-Bench | Not measured | 1.3% | Only o3 Mini measured |
| WeirdML | Not measured | 43.7% | Only o3 Mini measured |
| Cybench | Not measured | 22.5% | Only o3 Mini measured |
| ALE-Bench | 1590.1 | Not measured | Only Muse Spark Open measured |
| LMArena Text: coding | Not measured | 1378 | Only o3 Mini measured |
| LMArena Text: software and IT | Not measured | 1364 | Only o3 Mini 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 18 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Muse Spark Open | o3 Mini | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 12.5 | Only o3 Mini measured |
| Epoch Capabilities Index | 155.1 | 140.2 | Muse Spark Open |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | Muse Spark Open | o3 Mini | 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 |
| τ²-Bench Telecom | Not measured | 31.3% | Only o3 Mini measured |
| APEX-Agents | 33.4% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 30 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Muse Spark Open | o3 Mini | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 75.5% | Only o3 Mini measured |
| LiveBench reasoning | 73.7% | Not measured | Only Muse Spark Open measured |
| GPQA Diamond (Artificial Analysis run) | 89.0% | 77.3% | Muse Spark Open |
| Humanity's Last Exam (Artificial Analysis run) | 43.9% | 12.0% | Muse Spark Open |
| GPQA Diamond (Epoch AI run) | Not measured | 77.0% | Only o3 Mini measured |
| ARC-AGI | Not measured | 34.5% | Only o3 Mini measured |
| ARC-AGI-2 | Not measured | 3.0% | Only o3 Mini measured |
| SimpleBench | Not measured | 22.8% | Only o3 Mini measured |
| Chess puzzles | Not measured | 15.0% | Only o3 Mini measured |
| Mystery game puzzles | Not measured | 7.0% | Only o3 Mini measured |
| LMArena Text: hard prompts | Not measured | 1365 | Only o3 Mini measured |
| LMArena Text: expert | Not measured | 1364 | Only o3 Mini measured |
| LMArena Text: hard prompts in English | Not measured | 1375 | Only o3 Mini measured |
| Neither model has a result on the other 8 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | Muse Spark Open | o3 Mini | Leader |
|---|---|---|---|
| AIME | Not measured | 86.5% | Only o3 Mini measured |
| MATH 500 (Vals AI) | Not measured | 91.8% | Only o3 Mini measured |
| MGSM (Vals AI) | Not measured | 91.3% | Only o3 Mini measured |
| OTIS Mock AIME | Not measured | 76.9% | Only o3 Mini measured |
| FrontierMath, tiers 1 to 3 | Not measured | 18.6% | Only o3 Mini measured |
| FrontierMath, tier 4 | Not measured | 0.0% | Only o3 Mini measured |
| MATH level 5 | Not measured | 96.5% | Only o3 Mini measured |
| LMArena Text: math | Not measured | 1396 | Only o3 Mini measured |
| LMArena Text: mathematical work | Not measured | 1399 | Only o3 Mini measured |
| Neither model has a result on the other 4 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index11 boards, none shared
| Benchmark | Muse Spark Open | o3 Mini | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 78.7% | Only o3 Mini measured |
| LegalBench (Vals AI) | Not measured | 71.5% | Only o3 Mini measured |
| CorpFin (Vals AI) | Not measured | 45.3% | Only o3 Mini measured |
| TaxEval (Vals AI) | Not measured | 69.4% | Only o3 Mini measured |
| MedQA (Vals AI) | Not measured | 94.8% | Only o3 Mini measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 80.2% | Only o3 Mini measured |
| SimpleQA Verified | Not measured | 15.3% | Only o3 Mini measured |
| LMArena Text: science | Not measured | 1339 | Only o3 Mini measured |
| LMArena Text: medicine and healthcare | Not measured | 1330 | Only o3 Mini measured |
| LMArena Text: legal and government | Not measured | 1328 | Only o3 Mini measured |
| LMArena Text: business and finance | Not measured | 1313 | Only o3 Mini measured |
| Neither model has a result on the other 6 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | Muse Spark Open | o3 Mini | 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 | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Muse Spark Open | o3 Mini | Leader |
|---|---|---|---|
| LiveBench data analysis | 60.2% | Not measured | Only Muse Spark Open measured |
| IFBench | Not measured | 67.1% | Only o3 Mini measured |
| Long context reasoning (AA-LCR) | 78.3% | 43.0% | Muse Spark Open |
| DTBench | Not measured | 68.8% | Only o3 Mini measured |
| LMCA | Not measured | 19.0% | Only o3 Mini measured |
| Fiction.LiveBench | Not measured | 50.0% | Only o3 Mini measured |
| Creative writing (Lech Mazur) | Not measured | 61.7% | Only o3 Mini measured |
| LMArena Text | Not measured | 1337 | Only o3 Mini measured |
| LMArena Text: instruction following | Not measured | 1337 | Only o3 Mini measured |
| LMArena Text: creative writing | Not measured | 1286 | Only o3 Mini measured |
| LMArena Text: English | Not measured | 1351 | Only o3 Mini measured |
| LMArena Text: non-English | Not measured | 1319 | Only o3 Mini measured |
| LMArena Text: Chinese | Not measured | 1379 | Only o3 Mini measured |
| LMArena Text: German | Not measured | 1303 | Only o3 Mini measured |
| LMArena Text: Japanese | Not measured | 1286 | Only o3 Mini measured |
| LMArena Text: Korean | Not measured | 1313 | Only o3 Mini measured |
| LMArena Text: French | Not measured | 1334 | Only o3 Mini measured |
| LMArena Text: Spanish | Not measured | 1321 | Only o3 Mini measured |
| LMArena Text: Russian | Not measured | 1304 | Only o3 Mini measured |
| LMArena Text: Polish | Not measured | 1294 | Only o3 Mini measured |
| LMArena Text: multi-turn | Not measured | 1320 | Only o3 Mini measured |
| LMArena Text: longer queries | Not measured | 1343 | Only o3 Mini measured |
| LMArena Text: writing and language | Not measured | 1313 | Only o3 Mini measured |
| LMArena Text: entertainment and media | Not measured | 1283 | Only o3 Mini measured |
| Neither model has a result on the other 22 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | o3 Mini | 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
o3 Mini costs less
Repository review
50K input + 3K output tokens
o3 Mini costs less
Agent loop
200K input + 10K output tokens
o3 Mini 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 Mini |
|---|---|---|
| Maker | Meta | OpenAI |
| Weights | Open weights | No public weights listed |
| Released | October 15, 2026 | January 31, 2025 |
| Context window | 1.05M | 200K |
| Input $/Mtok | $1.25 | $1.10 |
| Output $/Mtok | $4.25 | $4.40 |
| Coding index | 62.1 | 52.1 |
| Independent measurements behind it | 2 | 2 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark Open better than o3 Mini for coding?
Pick Muse Spark Open for coding: it scores 62.1 on the Vibe Coding Index against 52.1 for o3 Mini. o3 Mini is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Which is cheaper, Muse Spark Open or o3 Mini?
Muse Spark Open costs $1.25 per million input tokens and $4.25 per million output tokens; o3 Mini costs $1.10 and $4.40. Cost per solved task is known for neither of them.
Which has the bigger context window, Muse Spark Open or o3 Mini?
Muse Spark Open, with 1.05M tokens against 200K.
How many benchmarks is the Muse Spark Open vs o3 Mini comparison based on?
5 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 Mini's on 2. Where only one model has a result, the page says so instead of naming a winner.