STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Inkling-Small vs Muse Spark Open

Muse Spark Open leads Inkling-Small by 16.5 points on StealthMark, 44.1 to 27.6. It leads on 8 of 9 benchmarks, including Latch, and Inkling-Small on 1, including Foresight. Muse Spark Open scores higher on Ground Truth.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

27.6/100Overall rank 43/53
44.1/100Overall rank 29/53

General Intelligence

25.5/100
42.6/100

Visual Intelligence

31.1/100
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

  • Inkling-Small
  • Muse Spark Open

Open or local

Open modelApache 2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • Inkling-Small
  • Muse Spark Open
  • Other models
  • Median

DATASHEET

Specs and pricing

Both take about 1M tokens of context.

  • Inkling-Small
  • Muse Spark Open
  • Other models
  • Median
PricePer 1M output tokens, input below
Inkling-Small: No list priceMuse Spark Open: $4.25$1.25 input
Context windowTokens per request, max output below
Inkling-Small: 1MTiedMuse Spark Open: 1MTied1M max output
Output speedTokens per second, our measurement
Inkling-Small: Not measuredMuse Spark Open: 361tokens/s
SizeTotal and active parameters
Inkling-Small: 276B12B activeMuse Spark Open: 816B42B active
Developer
Thinking Machines LabMeta
Released
Not published15 Oct 2026
Origin
Not publishedUnited States
Input → output
Text, image, audio → textText, image, audio, video → text
Architecture
42-layer decoder-only transformer with sparse mixture-of-experts feed-forward (6 of 256 routed experts plus 2 shared per token); hybrid local and global attention; natively multimodal with a hierarchical patch image encoder and discrete-token audioSparse 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 sourceInkling-Small ↗Muse 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.

Inkling-Small 30.2/100Rank 29/49

Survived 0 of 3
Foresight: complete playing field
Level 38 ptsTurn 17 / 20

Muse Spark Open 29.4/100Rank 34/49

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

Points per level

LevelInkling-SmallMuse Spark Open
Level 1Second Thoughts
9 ptsOut of lives
4 ptsOut of lives
Level 2Pressure Pot
6 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
8 ptsOut of lives
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.

Inkling-Small 34.7/100Rank 34/50

Cleared 3 of 5
Latch: complete playing field
Level 518 ptsTurn 40 / 40

Muse Spark Open 75.7/100Rank 13/50

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

Points per level

LevelInkling-SmallMuse Spark Open
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.8 ptsCleared
Level 3Relay vault
2.8 ptsFinished early
19.2 ptsCleared
Level 4Passing bay
8 ptsFinished early
17.8 ptsClearedFinished early · 1 beacon left
Level 5Second thoughts
18 ptsCleared
19.6 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

Inkling-Small

The sphere's apparent floor support, separate dark feature and broad paint ordering justify partial state credit. The major weakness is the largely missing mirror system: isolated side images and faint floor echoes do not establish repeated virtual rooms or curved spherical mapping. Downward framing, the oversized frontal panel, unresolved paint transport and satin surface appearance remain distinct limitations.

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

CategoryInkling-SmallMuse Spark Open
State at 600 ms14.0/2514.0/25
Camera and placement3.0/156.0/15
Reflections8.0/1208.0/120
Materials and scale2.5/103.5/10
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

Inkling-Small

The faces and dripping caps communicate a cute mushroom scene, but simple construction and weak spatial relationships limit the result. The defining foot-stamping action is unresolved, the flattering portrait is smaller than its painter, and the requested material contrasts are only partly conveyed.

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

CategoryInkling-SmallMuse Spark Open
Task & likeness2.5/105.0/10
Anatomy & construction1.5/104.5/10
Space & placement3.5/106.0/10
Light & reflections3.0/105.0/10
Purposeful detail4.5/106.0/10
Artistry & character3.0/105.0/10
Materials & effects3.5/105.0/10
Visual integrity2.0/106.5/10

Benchmark task

Inkling-Small

Character scenes test expression, anatomy, materials and coherent visual construction.

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

Inkling-Small

A recognizable but rudimentary Mona Lisa interpretation. Facial shading and subdued colors provide coherence, while the frontal blocklike torso, unresolved wrists, fingerless hands and shallow landscape substantially limit likeness, construction and finish.

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

CategoryInkling-SmallMuse Spark Open
Task & likeness2.5/103.0/10
Anatomy & construction2.5/103.0/10
Space & placement3.0/105.0/10
Light & reflections2.5/104.5/10
Purposeful detail2.0/104.0/10
Artistry & character2.5/103.0/10
Materials & effects2.0/104.0/10
Visual integrity3.0/106.0/10

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

Inkling-Small

A recognizable sunset beach with a clear focal sun and appealing color transitions. Connected fish silhouettes and layered scenery establish basic coherence. Primitive figures, ambiguous recreation, sparse descriptive detail and weak grounding limit construction and depth. The aligned reflection supplies a useful lighting cue, but shadows and material effects remain underdeveloped.

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

CategoryInkling-SmallMuse Spark Open
Task & likeness3.5/108.0/10
Anatomy & construction3.0/106.0/10
Space & placement3.0/106.5/10
Light & reflections3.0/105.5/10
Purposeful detail3.0/106.5/10
Artistry & character3.0/105.5/10
Materials & effects2.5/106.0/10
Visual integrity2.0/108.0/10

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

Inkling-Small

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

Inkling-Small

Recognizable animals, readable accessories and an appealing sunset support a coherent basic cartoon. Rounded construction leaves joints, riding support and steering unresolved. Decorative gradients contribute atmosphere, but directional lighting, distinct materials and convincing water displacement are weakly demonstrated.

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

CategoryInkling-SmallMuse Spark Open
Task & likeness4.0/104.0/10
Anatomy & construction3.0/103.0/10
Space & placement4.0/106.0/10
Light & reflections5.0/104.5/10
Purposeful detail5.5/107.0/10
Artistry & character4.0/103.5/10
Materials & effects5.0/105.0/10
Visual integrity5.0/105.0/10

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

Inkling-Small

The pelican is immediately recognizable, and its sweeping neck, shaped bill and orderly spokes provide character. Riding remains only partially realized: legs, pedal engagement, steering and seat support cannot be read confidently. Controlled graphic effects add atmosphere, but simplified construction and weak grounding keep the result basic.

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

CategoryInkling-SmallMuse Spark Open
Task & likeness4.0/107.5/10
Anatomy & construction3.0/105.0/10
Space & placement3.0/106.0/10
Light & reflections3.0/105.0/10
Purposeful detail4.5/106.5/10
Artistry & character5.0/105.5/10
Materials & effects4.5/106.0/10
Visual integrity3.0/107.5/10

Benchmark task

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