STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Cat Jam Free vs Muse Spark Open

Muse Spark Open leads Cat Jam Free by 10.6 points on StealthMark, 44.1 to 33.5. It leads on 6 of 9 benchmarks, including Latch, and Cat Jam Free on 3, including Foresight. Muse Spark Open scores higher on Ground Truth.

See the difference ↘
Model guide ↗
All results ↗

Overall StealthMark

33.5/100Overall rank 40/53
44.1/100Overall rank 29/53

General Intelligence

27.7/100
42.6/100

Visual Intelligence

43.0/100
46.6/100

Reasoning efficiency

On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.

Single-step reasoning Result quality weighed against reasoning tokens on a single problem

Multi-step reasoning Result quality weighed against reasoning tokens across connected steps, as in agentic workflows

  • Muse Spark Open

Open or local

NeitherApache-2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • Cat Jam Free
  • Muse Spark Open
  • Other models
  • Median

DATASHEET

Specs and pricing

  • Cat Jam Free
  • Muse Spark Open
  • Other models
  • Median
PricePer 1M output tokens, input below
Cat Jam Free: No list priceMuse Spark Open: $4.25$1.25 input
Context windowTokens per request, max output below
Cat Jam Free: Not publishedMuse Spark Open: 1M1M max output
Output speedTokens per second, our measurement
Cat Jam Free: Not measuredMuse Spark Open: 361tokens/s
SizeTotal and active parameters
Cat Jam Free: Not disclosedMuse Spark Open: 816B42B active
Developer
Not publishedMeta
Released
Not published15 Oct 2026
Origin
Not publishedUnited States
Input → output
Not publishedText, image, audio, video → text
Architecture
Not publishedSparse mixture-of-experts Transformer with perception encoders; 62 decoder layers, 256 experts with 8 selected per token, grouped-query attention and sliding-window/full-attention layers.

Full datasheets, every price and sourceMuse Spark Open ↗

Anticipating threats and planning ahead. Collect coins while avoiding ghosts. Ghosts move before the player each turn, and collisions cost a life. 3 levels in sequence, up to 66 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

Cat Jam Free 33.8/100Rank 26/47

Survived 1 of 3
Foresight: complete playing field
Level 39 ptsTurn 20 / 20

Muse Spark Open 29.4/100Rank 34/47

Survived 0 of 3
Foresight: complete playing field
Level 38 ptsTurn 15 / 20

Points per level

LevelCat Jam FreeMuse Spark Open
Level 1Second Thoughts
5 ptsOut of lives
4 ptsOut of lives
Level 2Pressure Pot
6 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
9 ptsSurvived
8 ptsOut of lives

Cooperative planning and learning from experience. Coordinate two robots to push numbered cores onto matching sockets. Pressure plates hold doors open; moving either robot uses one turn. 5 levels in sequence, up to 152 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

Cat Jam Free 33.9/100Rank 33/48

Cleared 2 of 5
Latch: complete playing field
Level 56 ptsTurn 25 / 40

Muse Spark Open 75.7/100Rank 12/48

Cleared 5 of 5
Latch: complete playing field
Level 519.6 ptsTurn 32 / 40

Points per level

LevelCat Jam FreeMuse Spark Open
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.8 ptsCleared
Level 3Relay vault
10 ptsFinished early
19.2 ptsCleared
Level 4Passing bay
10.8 ptsFinished early
17.8 ptsClearedFinished early · 1 beacon left
Level 5Second thoughts
6 ptsFinished early
19.6 ptsCleared

Newton's Mirror

Same task instructions

Physics, perspective and recursive reflections, tested together. Explore the test ↗

The judgment

Cat Jam Free

The image conveys a supported central sphere, separate black paint and crimson below cyan. Its contact and transport story is partially resolved. The exterior cutaway camera and largely missing mirror system dominate the limitations; isolated discs and smooth highlights provide little coherent optical structure.

Muse Spark Open

The airborne black blob and deformed paint support the broad contact sequence, although cyan attachment and wheel-directed transport remain partial. The sphere and black blob have substantial framing errors. The dominant limitation is the largely absent mirror system: faint wall circles and isolated highlights provide little evidence of recursive room geometry or curved nested reflections. Oversized compact paint features and diffuse material treatment further limit credit.

Score breakdown

CategoryCat Jam FreeMuse Spark Open
State at 600 ms14.0/2514.0/25
Camera and placement4.0/156.0/15
Reflections3.5/1208.0/120
Materials and scale4.0/103.5/10
Floor-damage reward0.0/100.0/10

Benchmark task

A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.

Selfie

Different task instructions

Visual construction and creative interpretation.

The judgment

Cat Jam Free

A coherent, restrained cat illustration captures the pale palette and intent eyes. Its central expressive requirement—the committed forward-and-down neck bob—is insufficiently articulated. Simple geometry, faint paw construction and minimal surface detail limit the physical presence and finish.

Muse Spark Open

The rounded silhouette and asymmetric expression make an appealing baby elephant, supported by a quiet background and grounding shadow. The protective action remains difficult to read: forefeet cannot be confidently traced into a grip, and seed contact is crowded by fine lines. Controlled simple shapes provide charm, but limited anatomical clarity, shading and surface detail leave the execution uneven.

Score breakdown

CategoryCat Jam FreeMuse Spark Open
Task & likeness5.5/105.0/10
Anatomy & construction5.5/104.5/10
Space & placement6.0/106.0/10
Light & reflections6.0/105.0/10
Purposeful detail4.0/106.0/10
Artistry & character5.5/105.0/10
Materials & effects5.0/105.0/10
Visual integrity6.5/106.5/10

Benchmark task

Cat Jam Free

An ivory cat nods intently to music beside a tiny speaker. The scene tests feline anatomy, movement conveyed through a still pose and the contrast between pale fur and woven fabric.

Muse Spark Open

A small elephant protecting a delicate seed tests expressive anatomy, physical contact and contrasting organic materials.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

Cat Jam Free

The portrait is recognizable and cleanly assembled, but replication remains basic. Its frontal symmetry, elongated silhouette, simplified facial likeness and unresolved hands differ markedly from the original. Modest skin gradients provide volume, while clothing and landscape rely on broad, flat shapes.

Muse Spark Open

A recognizable, orderly interpretation with clean major contours, connected body forms and modest facial shading. Wide eyes, frontal symmetry and schematic hands limit likeness and expression. Layered scenery establishes basic depth, but shallow arm overlaps, flat clothing and sparse fine detail keep the execution basic and uneven.

Score breakdown

CategoryCat Jam FreeMuse Spark Open
Task & likeness2.5/103.0/10
Anatomy & construction2.0/103.0/10
Space & placement4.0/105.0/10
Light & reflections3.5/104.5/10
Purposeful detail3.0/104.0/10
Artistry & character3.0/103.0/10
Materials & effects2.5/104.0/10
Visual integrity5.5/106.0/10

Benchmark task

An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.

Beach

Different task instructions

Creativity, perspective and visual beauty.

The judgment

Cat Jam Free

The scene clearly supplies the requested beach subjects and playful activity. Clean silhouettes and warm gradients support readability, but elementary drawing, ambiguous parasol construction, weak grounding and a rigid sun reflection limit its depth and finish.

Muse Spark Open

A coherent sunset beach with readable activities, balanced framing and controlled colour transitions. Small accessories add interest, but schematic anatomy, limited surface detail, weak directional shadows and a geometric reflection constrain its finish. Most shapes and overlaps remain clean.

Score breakdown

CategoryCat Jam FreeMuse Spark Open
Task & likeness7.0/108.0/10
Anatomy & construction4.5/106.0/10
Space & placement4.5/106.5/10
Light & reflections4.0/105.5/10
Purposeful detail4.0/106.5/10
Artistry & character4.5/105.5/10
Materials & effects4.5/106.0/10
Visual integrity5.5/108.0/10

Benchmark task

A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.

Ground Truth

Same task instructions

Physical reasoning, light and visual reconstruction.

The judgment

Cat Jam Free

This benchmark has not been assessed yet.

Muse Spark Open

This benchmark has not been assessed yet.

Benchmark task

A plank, computer mouse and blueberry in a steel room test physical stability, spatial relationships, materials and lighting.

Raccoon

Different task instructions

Scene composition and interacting subjects.

The judgment

Cat Jam Free

An appealing cartoon demonstrates the back-riding arrangement through expressive faces and clean shapes. Uncertain steering contact, indistinct deck support and weak hull-water interaction limit physical coherence. Smooth gradients add volume, but simple rounded construction and sparse material detail constrain complexity and finish.

Muse Spark Open

Expressive faces, distinct accessories and clean color separation make the scene appealing and recognizable. Character detail is stronger than the functional construction: steering contact, limb overlaps and seating remain ambiguous. The readable hull and lively spray establish motion, while limited directional shading and simplified surfaces constrain depth and physical coherence.

Score breakdown

CategoryCat Jam FreeMuse Spark Open
Task & likeness6.0/104.0/10
Anatomy & construction5.0/103.0/10
Space & placement5.0/106.0/10
Light & reflections5.0/104.5/10
Purposeful detail6.0/107.0/10
Artistry & character5.0/103.5/10
Materials & effects5.0/105.0/10
Visual integrity4.5/105.0/10

Benchmark task

A jet-ski scene pairs a canine driver with a raccoon passenger. It tests the placement and contact of interacting subjects, along with vehicle construction.

Pelican

Different task instructions

Subject construction and spatial relationships.

The judgment

Cat Jam Free

A coherent cartoon with readable bicycle placement, controlled outlines and modest surface shading. The separated-looking upper bill weakens pelican likeness; schematic limbs, uncertain gripping contact and simplified mechanics constrain construction. Opaque wheel interiors flatten spatial relationships. Limited feather complexity and directional lighting keep the finish modest.

Muse Spark Open

A controlled, appealing cartoon with a recognizable pelican, expressive face and clean curved forms. Feather lines, spokes and bill shading provide useful complexity. Aligned wheels and a ground shadow establish placement, but uncertain pedal contacts and obscured mechanical connections weaken support and riding action. Lighting remains loosely coordinated with the sun.

Score breakdown

CategoryCat Jam FreeMuse Spark Open
Task & likeness7.0/107.5/10
Anatomy & construction5.0/105.0/10
Space & placement6.0/106.0/10
Light & reflections5.0/105.0/10
Purposeful detail5.5/106.5/10
Artistry & character5.5/105.5/10
Materials & effects6.5/106.0/10
Visual integrity6.5/107.5/10

Benchmark task

A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.