Muse Spark Open vs Nemotron 3.5 Lightning
Muse Spark Open leads Nemotron 3.5 Lightning on coding, 47.4 to 22.6 on the Vibe Coding Index, and Nemotron 3.5 Lightning costs 28.9x less per output token ($0.147 vs $4.25 per million). Updated October 22, 2026; 11 benchmarks have a result for both.
Muse Spark Open or Nemotron 3.5 Lightning: which to pick
Pick Muse Spark Open for coding: it scores 47.4 on the Vibe Coding Index against 22.6 for Nemotron 3.5 Lightning.
Pick Nemotron 3.5 Lightning for output tokens 28.9x cheaper ($0.147 vs $4.25 per million).
- Shared results
- 11
- Muse Spark Open only
- 17
- Nemotron 3.5 Lightning only
- 9
- 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
Muse Spark Open
Muse Spark Open scores 47.4 against 22.6.
4 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Nemotron 3.5 Lightning has a AA Intelligence Index result, 12.9.
Directional only
Agentic work
AA Agentic Index
No call
Only Nemotron 3.5 Lightning has a AA Agentic Index result, 3.5.
Directional only
Web design
Design Arena: websites
No call
Only Muse Spark Open has a Design Arena: websites result, 1310.
Directional only
General
Vals Index
No call
Only Muse Spark Open has a Vals Index result, 48.6%.
Directional only
Long documents
Listed context window
Muse Spark Open
Muse Spark Open takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Nemotron 3.5 Lightning
Muse Spark Open $0.0034, Nemotron 3.5 Lightning $0.0001 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Nemotron 3.5 Lightning has the number, $0.06.
Directional only
At a glance
- Coding index
- Muse Spark Open 47.4 from 4 benchmarks, Nemotron 3.5 Lightning 22.6 from 2 benchmarks.
- Widest category
- Coding, 37.0 points apart on average over 4 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Muse Spark Open 76.2% against Nemotron 3.5 Lightning 0.0%, 76.2 points apart on a 0 to 100 scale.
- Output price
- Muse Spark Open $4.25 against Nemotron 3.5 Lightning $0.147 per million output tokens, 28.9x apart.
- Context window
- Muse Spark Open takes 1.05M tokens, Nemotron 3.5 Lightning 262K.
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 | Nemotron 3.5 Lightning | Ties |
|---|---|---|---|---|
| Coding | 4 | 0 | ||
| Agentic work | 4 | 0 | ||
| Reasoning | 2 | 0 | ||
| General | 1 | 0 | ||
| All shared boards | 11 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index40
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| LiveBench coding | 73.6% | Not measured | Only Muse Spark Open measured |
| LMArena WebDev | 1528 | Not measured | Only Muse Spark Open measured |
| AA Coding Index | Not measured | 26.8 | Only Nemotron 3.5 Lightning measured |
| SWE-bench Verified (Vals AI) | Not measured | 52.8% | Only Nemotron 3.5 Lightning measured |
| Terminal-Bench 4 (Vals AI) | 6.6% | Not measured | Only Muse Spark Open measured |
| Vibe Code Bench (Vals AI) | 76.2% | 0.0% | Muse Spark Open |
| Code migration (Vals AI) | 21.2% | 3.0% | Muse Spark Open |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Nemotron 3.5 Lightning measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 10.9% | Only Nemotron 3.5 Lightning measured |
| CyberBench (Vals AI) | Not measured | 29.5% | Only Nemotron 3.5 Lightning measured |
| SciCode | 58.4% | 32.1% | Muse Spark Open |
| ALE-Bench | 1590.1 | 769.2 | Muse Spark Open |
| 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 25 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 12.9 | Only Nemotron 3.5 Lightning measured |
| Epoch Capabilities Index | 155.1 | Not measured | Only Muse Spark Open measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 3.5 | Only Nemotron 3.5 Lightning measured |
| 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% | 18.5% | Muse Spark Open |
| Tax Agent Bench (Vals AI) | 26.3% | 2.6% | Muse Spark Open |
| Legal Research Bench (Vals AI) | 38.5% | 2.9% | Muse Spark Open |
| Harvey's Legal Agent Benchmark (Vals AI) | 25.0% | Not measured | Only Muse Spark Open measured |
| Excel Modeling Benchmark (Vals AI) | 53.7% | 17.0% | Muse Spark Open |
| 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 index20
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| LiveBench reasoning | 73.7% | Not measured | Only Muse Spark Open measured |
| GPQA Diamond (Artificial Analysis run) | 89.0% | 74.3% | Muse Spark Open |
| Humanity's Last Exam (Artificial Analysis run) | 43.9% | 10.6% | Muse Spark Open |
| Neither model has a result on the other 19 boards here | |||
MathNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| Neither model has a result on 13 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| CorpFin (Vals AI) | Not measured | 54.2% | Only Nemotron 3.5 Lightning measured |
| Neither model has a result on the other 17 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| Design Arena: websites | 1310 | Not measured | Only Muse Spark Open measured |
| Design Arena: game dev | 1282 | 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 | Nemotron 3.5 Lightning | Leader |
|---|---|---|---|
| Vals Index | 48.6% | Not measured | Only Muse Spark Open measured |
| LiveBench data analysis | 60.2% | Not measured | Only Muse Spark Open measured |
| MedScribe (Vals AI) | Not measured | 4.3% | Only Nemotron 3.5 Lightning measured |
| Long context reasoning (AA-LCR) | 78.3% | 60.3% | Muse Spark Open |
| Neither model has a result on the other 42 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | Nemotron 3.5 Lightning | 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
Nemotron 3.5 Lightning costs less
Repository review
50K input + 3K output tokens
Nemotron 3.5 Lightning costs less
Agent loop
200K input + 10K output tokens
Nemotron 3.5 Lightning 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 | NVIDIA Nemotron 3.5 Lightning |
|---|---|---|
| Maker | Meta | NVIDIA |
| Weights | Open weights | Open weights |
| Released | October 15, 2026 | August 11, 2026 |
| Context window | 1.05M | 262K |
| Input $/Mtok | $1.25 | $0.0534 |
| Output $/Mtok | $4.25 | $0.147 |
| Coding index | 47.4 | 22.6 |
| Independent measurements behind it | 4 | 2 |
| Cost per solved task | Not computable | $0.06 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark Open better than Nemotron 3.5 Lightning for coding?
Pick Muse Spark Open for coding: it scores 47.4 on the Vibe Coding Index against 22.6 for Nemotron 3.5 Lightning. Pick Nemotron 3.5 Lightning for output tokens 28.9x cheaper ($0.147 vs $4.25 per million).
Which is cheaper, Muse Spark Open or Nemotron 3.5 Lightning?
Muse Spark Open costs $1.25 per million input tokens and $4.25 per million output tokens; Nemotron 3.5 Lightning costs $0.0534 and $0.147. Cost per solved task is known for Nemotron 3.5 Lightning only.
Which has the bigger context window, Muse Spark Open or Nemotron 3.5 Lightning?
Muse Spark Open, with 1.05M tokens against 262K.
How many benchmarks is the Muse Spark Open vs Nemotron 3.5 Lightning comparison based on?
11 benchmarks have a result for both models as of October 22, 2026. Muse Spark Open's coding index rests on 4 independent benchmarks and Nemotron 3.5 Lightning's on 2. Where only one model has a result, the page says so instead of naming a winner.