Muse Spark Open vs Fugu Ultra v2
Muse Spark Open costs 7.1x less per output token than Fugu Ultra v2 ($4.25 vs $30.00 per million). Updated October 23, 2026; no benchmark has tested both models yet.
- Coding
- 47.3
- Overall
- 44.9
- Output $/M
- $4.25
- Coding
- No data
- Overall
- No data
- Output $/M
- $30.00
Muse Spark Open or Fugu Ultra v2: which to pick
Only Muse Spark Open has a coding score, 47.3 on the Vibe Coding Index; Fugu Ultra v2 has none, so the two cannot be ranked on coding.
Compare them on price, context and the boards below.
No benchmark has tested both yet. Muse Spark Open has results on LiveBench coding, LMArena WebDev and Terminal-Bench 4 (Vals AI); Fugu Ultra v2 has none yet. Compare them on price and context instead.
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 Open has a coding score, so no call is made.
One side not measured
Web design
Design Arena: websites
No call
Only Muse Spark Open has a Design Arena: websites result, 1320.
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 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Spark Open
Muse Spark Open $0.0034, Fugu Ultra v2 $0.020 per turn.
List prices
At a glance
- Coding index
- Muse Spark Open 47.3 from 4 benchmarks, Fugu Ultra v2 not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- Muse Spark Open $4.25 against Fugu Ultra v2 $30.00 per million output tokens, 7.1x apart.
- Context window
- Muse Spark Open takes 1.05M tokens, Fugu Ultra v2 1M.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index10 boards measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | Leader |
|---|---|---|---|
| LiveBench coding | 73.6% | Not measured | Only Muse Spark Open measured |
| LMArena WebDev | 1527 | 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 |
| ALE-Bench | 1590.1 | Not measured | Only Muse Spark Open measured |
| LMArena WebDev: React | 1528 | Not measured | Only Muse Spark Open measured |
| LMArena WebDev: HTML | 1489 | Not measured | Only Muse Spark Open measured |
| SWE-Bench Pro V2 | 95.0% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 33 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 155.1 | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index9 boards measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | 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 |
| Harvey's Legal Agent Benchmark (Vals AI) | 25.0% | 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 33 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | Leader |
|---|---|---|---|
| LiveBench reasoning | 73.7% | Not measured | Only Muse Spark Open measured |
| GPQA Diamond (Artificial Analysis run) | 89.0% | Not measured | Only Muse Spark Open measured |
| Humanity's Last Exam (Artificial Analysis run) | 43.9% | Not measured | Only Muse Spark Open measured |
| Humanity's Last Exam (Scale run) | 28.0% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 19 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | Leader |
|---|---|---|---|
| MathArena | 33.6% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 13 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | Leader |
|---|---|---|---|
| PRBench Legal | 59.8% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 19 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index3 boards measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | Leader |
|---|---|---|---|
| Design Arena: websites | 1320 | Not measured | Only Muse Spark Open measured |
| Design Arena: game dev | 1288 | 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 index4 boards measured
| Benchmark | Muse Spark Open | Fugu Ultra v2 | Leader |
|---|---|---|---|
| Vals Index | 48.6% | Not measured | Only Muse Spark Open measured |
| 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 |
| MultiChallenge | 74.2% | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 44 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 | Sakana Fugu Ultra v2 |
|---|---|---|
| Maker | Meta | Sakana |
| Weights | Open weights | No public weights listed |
| Released | October 15, 2026 | September 11, 2026 |
| Context window | 1.05M | 1M |
| Input $/Mtok | $1.25 | $5.00 |
| Output $/Mtok | $4.25 | $30.00 |
| Coding index | 47.3 | Not benchmarked |
| Independent measurements behind it | 4 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark Open better than Fugu Ultra v2 for coding?
Only Muse Spark Open has a coding score, 47.3 on the Vibe Coding Index; Fugu Ultra v2 has none, so the two cannot be ranked on coding. Compare them on price, context and the boards below.
Which is cheaper, Muse Spark Open or Fugu Ultra v2?
Muse Spark Open costs $1.25 per million input tokens and $4.25 per million output tokens; Fugu Ultra v2 costs $5.00 and $30.00. Cost per solved task is known for neither of them.
Which has the bigger context window, Muse Spark Open or Fugu Ultra v2?
Muse Spark Open, with 1.05M tokens against 1M.
Has any benchmark tested both Muse Spark Open and Fugu Ultra v2?
No benchmark has tested both yet. Muse Spark Open has results on LiveBench coding, LMArena WebDev and Terminal-Bench 4 (Vals AI); Fugu Ultra v2 has none yet. Compare them on price and context instead. Data as of October 23, 2026.