Gemini 4 Hydrogen vs Muse Spark Open
Gemini 4 Hydrogen leads Muse Spark Open on coding, 77.9 to 43.4 on the Vibe Coding Index, and Muse Spark Open costs 1.8x less per output token ($4.25 vs $7.50 per million). Updated November 14, 2026; 25 benchmarks have a result for both.
Gemini 4 Hydrogen or Muse Spark Open: which to pick
Pick Gemini 4 Hydrogen for coding: it scores 77.9 on the Vibe Coding Index against 43.4 for Muse Spark Open.
Pick Muse Spark Open for output tokens 1.8x cheaper ($4.25 vs $7.50 per million) and work measured by Harvey's Legal Agent Benchmark (Vals AI), where it leads.
- Shared results
- 25
- Gemini 4 Hydrogen only
- 25
- Muse Spark Open only
- 22
- Like-for-like categories
- 6 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
Gemini 4 Hydrogen
Gemini 4 Hydrogen scores 77.9 against 43.4.
4 benchmarks behind each score
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
Gemini 4 Hydrogen
Gemini 4 Hydrogen leads, 1320 against 1306.
Same board, both measured
General
Vals Index
Gemini 4 Hydrogen
Gemini 4 Hydrogen leads, 68.5% 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
Muse Spark Open
Gemini 4 Hydrogen $0.0053, Muse Spark Open $0.0034 per turn.
List prices
At a glance
- Coding index
- Gemini 4 Hydrogen 77.9 from 4 benchmarks, Muse Spark Open 43.4 from 4 benchmarks.
- Widest category
- Coding, 29.3 points apart on average over 8 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Gemini 4 Hydrogen 54.0% against Muse Spark Open 6.6%, 63.3 points apart on a 0 to 100 scale.
- Output price
- Gemini 4 Hydrogen $7.50 against Muse Spark Open $4.25 per million output tokens, 1.8x 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 | Gemini 4 Hydrogen | Bars | Muse Spark Open | Ties |
|---|---|---|---|---|
| Coding | 8 | 0 | ||
| Agentic work | 5 | 1 | ||
| Reasoning | 3 | 0 | ||
| Knowledge | 1 | 0 | ||
| Web design | 5 | 0 | ||
| General | 2 | 0 | ||
| All shared boards | 24 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index80
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| LiveBench coding | 78.5% | 55.1% | Gemini 4 Hydrogen |
| LMArena WebDev | 1704 | 1526 | Gemini 4 Hydrogen |
| Terminal-Bench 4 (Vals AI) | 54.0% | 6.6% | Gemini 4 Hydrogen |
| Vibe Code Bench (Vals AI) | 87.8% | 76.2% | Gemini 4 Hydrogen |
| Code migration (Vals AI) | Not measured | 21.2% | Only Muse Spark Open measured |
| SciCode | Not measured | 58.4% | Only Muse Spark Open measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | 54.0% | 8.1% | Gemini 4 Hydrogen |
| FrontierCode 2.0 | 39.0% | 7.6% | Gemini 4 Hydrogen |
| ALE-Bench | Not measured | 1590.1 | Only Muse Spark Open measured |
| LMArena Text: coding | 1516 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: software and IT | 1513 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena WebDev: React | 1724 | 1523 | Gemini 4 Hydrogen |
| LMArena WebDev: HTML | 1743 | 1475 | Gemini 4 Hydrogen |
| SWE-Bench Pro V2 | Not measured | 95.0% | Only Muse Spark Open measured |
| GameBench 2 | Not measured | 59.3 | Only Muse Spark Open measured |
| CursorBench 4.0 | 57.8% | Not measured | Only Gemini 4 Hydrogen measured |
| Neither model has a result on the other 36 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 24.9 | Only Muse Spark Open measured |
| Epoch Capabilities Index | Not measured | 155.4 | Only Muse Spark Open measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index51
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| LiveBench research | 86.8% | 82.7% | Gemini 4 Hydrogen |
| LiveBench browser | 77.1% | 26.2% | Gemini 4 Hydrogen |
| LiveBench long agentic | 61.8% | 12.1% | Gemini 4 Hydrogen |
| Finance Agent (Vals AI) | Not measured | 61.3% | Only Muse Spark Open measured |
| Tax Agent Bench (Vals AI) | 52.3% | 26.3% | Gemini 4 Hydrogen |
| Legal Research Bench (Vals AI) | 53.8% | 38.5% | Gemini 4 Hydrogen |
| Harvey's Legal Agent Benchmark (Vals AI) | 11.3% | 25.0% | Muse Spark Open |
| Excel Modeling Benchmark (Vals AI) | Not measured | 53.7% | Only Muse Spark Open measured |
| APEX-Agents | Not measured | 33.4% | Only Muse Spark Open measured |
| Neither model has a result on the other 35 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| LiveBench reasoning | 88.6% | 73.7% | Gemini 4 Hydrogen |
| GPQA Diamond (Artificial Analysis run) | Not measured | 89.0% | Only Muse Spark Open measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 43.9% | Only Muse Spark Open measured |
| HLE-Diamond (Artificial Analysis run) | 58.8% | 26.3% | Gemini 4 Hydrogen |
| CritPt v2, hard subset (Artificial Analysis run) | 66.0% | 29.5% | Gemini 4 Hydrogen |
| ARC-AGI | Not measured | 89.0% | Only Muse Spark Open measured |
| ARC-AGI-2 | Not measured | 57.5% | Only Muse Spark Open measured |
| LMArena Text: hard prompts | 1520 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: expert | 1558 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: hard prompts in English | 1514 | Not measured | Only Gemini 4 Hydrogen measured |
| Humanity's Last Exam (Scale run) | Not measured | 28.0% | Only Muse Spark Open measured |
| Neither model has a result on the other 15 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| LMArena Text: math | 1507 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: mathematical work | 1534 | Not measured | Only Gemini 4 Hydrogen measured |
| MathArena | Not measured | 25.6% | Only Muse Spark Open measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| AA-Omniscience | 46.3 | 25.8 | Gemini 4 Hydrogen |
| LMArena Text: science | 1519 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: medicine and healthcare | 1488 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: legal and government | 1532 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: business and finance | 1486 | Not measured | Only Gemini 4 Hydrogen measured |
| PRBench Legal | Not measured | 59.8% | Only Muse Spark Open measured |
| Neither model has a result on the other 15 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| Design Arena: websites | 1320 | 1306 | Gemini 4 Hydrogen |
| Design Arena: UI components | Not measured | 1312 | Only Muse Spark Open measured |
| Design Arena: game dev | 1369 | 1265 | Gemini 4 Hydrogen |
| Design Arena: 3D | 1415 | 1247 | Gemini 4 Hydrogen |
| Design Arena: all code categories | 1333 | 1301 | Gemini 4 Hydrogen |
| LiveBench design | 77.3% | 58.1% | Gemini 4 Hydrogen |
| Neither model has a result on the other 3 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | Leader |
|---|---|---|---|
| Vals Index | 68.5% | 48.6% | Gemini 4 Hydrogen |
| LiveBench data analysis | 83.2% | 60.2% | Gemini 4 Hydrogen |
| SAGE (Vals AI) | Not measured | 85.8% | Only Muse Spark Open measured |
| Long context reasoning (AA-LCR) | Not measured | 78.3% | Only Muse Spark Open measured |
| GDPval-AA | Not measured | 1401 | Only Muse Spark Open measured |
| LMArena Text | 1502 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: instruction following | 1519 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: creative writing | 1509 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: English | 1499 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: non-English | 1495 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: Chinese | 1631 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: French | 1512 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: Spanish | 1494 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: Russian | 1492 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: multi-turn | 1485 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: longer queries | 1524 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: writing and language | 1500 | Not measured | Only Gemini 4 Hydrogen measured |
| LMArena Text: entertainment and media | 1503 | Not measured | Only Gemini 4 Hydrogen measured |
| MultiChallenge | Not measured | 74.2% | Only Muse Spark Open measured |
| Neither model has a result on the other 30 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 4 Hydrogen | Muse Spark Open | 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 | Google Gemini 4 Hydrogen | Meta Muse Spark Open |
|---|---|---|
| Maker | Meta | |
| Weights | No public weights listed | Open weights |
| Released | November 12, 2026 | October 15, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $1.50 | $1.25 |
| Output $/Mtok | $7.50 | $4.25 |
| Coding index | 77.9 | 43.4 |
| Independent measurements behind it | 4 | 4 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 4 Hydrogen better than Muse Spark Open for coding?
Pick Gemini 4 Hydrogen for coding: it scores 77.9 on the Vibe Coding Index against 43.4 for Muse Spark Open. Pick Muse Spark Open for output tokens 1.8x cheaper ($4.25 vs $7.50 per million) and work measured by Harvey's Legal Agent Benchmark (Vals AI), where it leads.
Which is cheaper, Gemini 4 Hydrogen or Muse Spark Open?
Gemini 4 Hydrogen costs $1.50 per million input tokens and $7.50 per million output tokens; Muse Spark Open costs $1.25 and $4.25. Cost per solved task is known for neither of them.
Which has the bigger context window, Gemini 4 Hydrogen or Muse Spark Open?
Neither: both take 1.05M tokens.
How many benchmarks is the Gemini 4 Hydrogen vs Muse Spark Open comparison based on?
25 benchmarks have a result for both models as of November 14, 2026. Gemini 4 Hydrogen's coding index rests on 4 independent benchmarks and Muse Spark Open's on 4. Where only one model has a result, the page says so instead of naming a winner.