Muse Spark Open vs Hy4
Hy4 leads Muse Spark Open on coding, 65.2 to 47.3 on the Vibe Coding Index, and Hy4 costs 3.4x less per output token ($1.2505 vs $4.25 per million). Updated November 5, 2026; 6 benchmarks have a result for both.
Muse Spark Open or Hy4: which to pick
Pick Hy4 for coding: it scores 65.2 on the Vibe Coding Index against 47.3 for Muse Spark Open, though on 2 benchmarks against 4.
Pick Muse Spark Open for work measured by Harvey's Legal Agent Benchmark (Vals AI), where it leads.
- Shared results
- 6
- Muse Spark Open only
- 35
- Hy4 only
- 0
- Like-for-like categories
- 3 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
Hy4
Hy4 scores 65.2 against 47.3.
4 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Muse Spark Open has a AA Intelligence Index result, 24.9.
Directional only
Web design
Design Arena: websites
No call
Only Muse Spark Open has a Design Arena: websites result, 1302.
Directional only
General
Vals Index
Hy4
Hy4 leads, 59.4% against 48.6%.
Same board, both measured
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Hy4
Muse Spark Open $0.0034, Hy4 $0.0010 per turn.
List prices
At a glance
- Coding index
- Muse Spark Open 47.3 from 4 benchmarks, Hy4 65.2 from 2 benchmarks.
- Widest category
- Coding, 24.3 points apart on average over 2 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Muse Spark Open 6.6% against Hy4 39.4%, 43.8 points apart on a 0 to 100 scale.
- Output price
- Muse Spark Open $4.25 against Hy4 $1.2505 per million output tokens, 3.4x apart.
- Context window
- Both take 1.05M tokens.
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 | Hy4 | Ties |
|---|---|---|---|---|
| Coding | 0 | 2 | ||
| Agentic work | 1 | 2 | ||
| General | 0 | 1 | ||
| All shared boards | 1 | 5 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index02
| Benchmark | Muse Spark Open | Hy4 | Leader |
|---|---|---|---|
| LiveBench coding | 73.6% | Not measured | Only Muse Spark Open measured |
| LMArena WebDev | 1526 | Not measured | Only Muse Spark Open measured |
| Terminal-Bench 4 (Vals AI) | 6.6% | 39.4% | Hy4 |
| Vibe Code Bench (Vals AI) | 76.2% | 81.0% | Hy4 |
| 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 | 1524 | Not measured | Only Muse Spark Open measured |
| LMArena WebDev: HTML | 1481 | Not measured | Only Muse Spark Open measured |
| SWE-Bench Pro V2 | 95.0% | Not measured | Only Muse Spark Open measured |
| GameBench 2 | 59.2 | Not measured | Only Muse Spark Open measured |
| Neither model has a result on the other 39 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Muse Spark Open | Hy4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 24.9 | Not measured | Only Muse Spark Open measured |
| Epoch Capabilities Index | 155.4 | Not measured | Only Muse Spark Open measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | Muse Spark Open | Hy4 | Leader |
|---|---|---|---|
| LiveBench research | 80.3% | Not measured | Only Muse Spark Open measured |
| LiveBench browser | 26.2% | Not measured | Only Muse Spark Open measured |
| LiveBench long agentic | 11.7% | 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% | 34.4% | Hy4 |
| Legal Research Bench (Vals AI) | 38.5% | 41.4% | Hy4 |
| Harvey's Legal Agent Benchmark (Vals AI) | 25.0% | 12.5% | Muse Spark Open |
| 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 35 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Muse Spark Open | Hy4 | 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 |
| ARC-AGI | 89.0% | Not measured | Only Muse Spark Open measured |
| ARC-AGI-2 | 57.5% | 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 18 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Muse Spark Open | Hy4 | Leader |
|---|---|---|---|
| MathArena | 33.1% | 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, none shared
| Benchmark | Muse Spark Open | Hy4 | 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 index6 boards, none shared
| Benchmark | Muse Spark Open | Hy4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1302 | Not measured | Only Muse Spark Open measured |
| Design Arena: UI components | 1328 | Not measured | Only Muse Spark Open measured |
| Design Arena: game dev | 1272 | Not measured | Only Muse Spark Open measured |
| Design Arena: 3D | 1261 | Not measured | Only Muse Spark Open measured |
| Design Arena: all code categories | 1301 | 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 3 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Muse Spark Open | Hy4 | Leader |
|---|---|---|---|
| Vals Index | 48.6% | 59.4% | Hy4 |
| LiveBench data analysis | 60.2% | Not measured | Only Muse Spark Open measured |
| SAGE (Vals AI) | 85.8% | 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 43 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Muse Spark Open | Hy4 | 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
Hy4 costs less
Repository review
50K input + 3K output tokens
Hy4 costs less
Agent loop
200K input + 10K output tokens
Hy4 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 | Tencent Hy4 |
|---|---|---|
| Maker | Meta | Tencent |
| Weights | Open weights | Open weights |
| Released | October 15, 2026 | November 4, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $1.25 | $0.417 |
| Output $/Mtok | $4.25 | $1.2505 |
| Coding index | 47.3 | 65.2 |
| Independent measurements behind it | 4 | 2 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Muse Spark Open better than Hy4 for coding?
Pick Hy4 for coding: it scores 65.2 on the Vibe Coding Index against 47.3 for Muse Spark Open, though on 2 benchmarks against 4. Pick Muse Spark Open for work measured by Harvey's Legal Agent Benchmark (Vals AI), where it leads.
Which is cheaper, Muse Spark Open or Hy4?
Muse Spark Open costs $1.25 per million input tokens and $4.25 per million output tokens; Hy4 costs $0.417 and $1.2505. Cost per solved task is known for neither of them.
Which has the bigger context window, Muse Spark Open or Hy4?
Neither: both take 1.05M tokens.
How many benchmarks is the Muse Spark Open vs Hy4 comparison based on?
6 benchmarks have a result for both models as of November 5, 2026. Muse Spark Open's coding index rests on 4 independent benchmarks and Hy4's on 2. Where only one model has a result, the page says so instead of naming a winner.