STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Kimi K3 vs Muse Spark Open

Kimi K3 leads Muse Spark Open by 6.5 points on StealthMark, 50.6 to 44.1. It leads on 7 of 9 benchmarks, including Foresight, and Muse Spark Open on 2, including Latch. Kimi K3 scores higher on Newton's Mirror, with its largest category advantage in reflections.

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All results ↗
All results ↗

Overall StealthMark

50.6/100Overall rank 15/53
44.1/100Overall rank 29/53

General Intelligence

44.4/100
42.6/100

Visual Intelligence

61.4/100
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

Open modelKimi K3 License

BENCHMARK BY BENCHMARK

Where each model leads

  • Kimi K3
  • Muse Spark Open
  • Other models
  • Median

DATASHEET

Specs and pricing

Kimi K3 scores higher on StealthMark. Muse Spark Open is 2.5× cheaper per output token and runs 3.1× faster in our speed test. Both take about 1M tokens of context.

  • Kimi K3
  • Muse Spark Open
  • Other models
  • Median
PricePer 1M output tokens, input below
Kimi K3: $10.80$0.24 inputMuse Spark Open: $4.252.5× cheaper$1.25 input
Context windowTokens per request, max output below
Kimi K3: 1MTied1M max outputMuse Spark Open: 1MTied1M max output
Output speedTokens per second, our measurement
Kimi K3: 115tokens/sMuse Spark Open: 3613.1× fastertokens/s
SizeTotal and active parameters
Kimi K3: 2.8T104B activeMuse Spark Open: 816B42B active
Developer
Moonshot AIMeta
Released
16 Jul 202615 Oct 2026
Origin
ChinaUnited States
Input → output
Text, image → textText, image, audio, video → text
Architecture
Mixture-of-Experts with KDA + Gated MLA attention, 896 experts and native vision encoderSparse 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 sourceKimi K3 ↗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.

Kimi K3 52.7/100Rank 16/47

Survived 0 of 3
Foresight: complete playing field
Level 311 ptsTurn 17 / 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

LevelKimi K3Muse Spark Open
Level 1Second Thoughts
17 ptsOut of lives
4 ptsOut of lives
Level 2Pressure Pot
10 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
11 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.

Kimi K3 57.7/100Rank 20/48

Cleared 3 of 5
Latch: complete playing field
Level 514.2 ptsTurn 4 / 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

LevelKimi K3Muse Spark Open
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.6 ptsCleared
9.8 ptsCleared
Level 3Relay vault
18.2 ptsClearedFinished early · 3 beacons left
19.2 ptsCleared
Level 4Passing bay
14.2 ptsFinished early
17.8 ptsClearedFinished early · 1 beacon left
Level 5Second thoughts
14.2 ptsFinished early
19.6 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

Kimi K3

The room fills the complete portrait frame without visible borders or labels. The main sphere and airborne black are convincingly placed within the portrait frame. Paint ordering is supported, but its contact and transport history remains weakly expressed. Symmetric wall ghosts, inverted floor imagery and panel echoes establish a basic mirror system. Diffuse gradients dominate, with little ordered nested imagery or repeated emitter mapping on either planar or spherical surfaces. The wall images sit too low, and the floor image is unusually large and low.

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

CategoryKimi K3Muse Spark Open
State at 600 ms18.0/2514.0/25
Camera and placement8.0/156.0/15
Reflections24.0/1208.0/120
Materials and scale6.5/103.5/10
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

Kimi K3

The indigo creature and warm reflected counterpart create a balanced, contemplative composition. Equations, constellations and book emblems give the transformation meaning. Clean silhouettes and controlled glow support the scene, but minimally articulated legs, shallow spatial cues and smooth, generalized surfaces limit its anatomical and material richness.

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

CategoryKimi K3Muse Spark Open
Task & likeness9.0/105.0/10
Anatomy & construction7.0/104.5/10
Space & placement8.0/106.0/10
Light & reflections7.5/105.0/10
Purposeful detail8.0/106.0/10
Artistry & character8.5/105.0/10
Materials & effects7.5/105.0/10
Visual integrity8.0/106.5/10

Benchmark task

Kimi K3

An imagined creature encounters its reflection. The scene tests original character design, visual self-interpretation and the relationship between a subject and its reflected image.

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

Kimi K3

The centered portrait, dark veil, folded hands and misty landscape clearly evoke Mona Lisa. Replication is limited by the elongated neck, simplified facial proportions and oval hands with shallow finger marks. Soft shading gives some volume, but pervasive blur substitutes for controlled painterly transitions and precise detail.

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

CategoryKimi K3Muse Spark Open
Task & likeness4.5/103.0/10
Anatomy & construction3.5/103.0/10
Space & placement4.5/105.0/10
Light & reflections4.5/104.5/10
Purposeful detail4.0/104.0/10
Artistry & character4.5/103.0/10
Materials & effects4.5/104.0/10
Visual integrity5.0/106.0/10

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

Kimi K3

A coordinated sunset palette, expressive silhouettes and varied small details create a lively, appealing beach illustration. The central sun and framing palm and umbrella organize the busy scene, with clean contours preserving readability. Bodies and people remain diagrammatic, depth is shallow, and inverted figure reflections cross matte-looking sand without convincing surface lighting. Materials and movement are mostly conveyed through flat shapes.

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

CategoryKimi K3Muse Spark Open
Task & likeness8.5/108.0/10
Anatomy & construction7.0/106.0/10
Space & placement7.0/106.5/10
Light & reflections6.5/105.5/10
Purposeful detail8.5/106.5/10
Artistry & character8.5/105.5/10
Materials & effects6.5/106.0/10
Visual integrity7.0/108.0/10

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

Kimi K3

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

Kimi K3

The raccoon rides on the dog's back, and the dog's paw meets a steering assembly connected to the red hull. Expressive faces, a warm sunset and sweeping spray create an appealing composition. Crowded body overlaps obscure some limb connections, and the raccoon's right ear appears slightly separated. Flat shading and stylized reflections limit volume and depth.

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

CategoryKimi K3Muse Spark Open
Task & likeness8.0/104.0/10
Anatomy & construction6.5/103.0/10
Space & placement7.5/106.0/10
Light & reflections7.0/104.5/10
Purposeful detail7.5/107.0/10
Artistry & character6.0/103.5/10
Materials & effects7.5/105.0/10
Visual integrity7.0/105.0/10

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

Kimi K3

The pelican and bicycle are immediately recognizable, with an expressive bill, flowing scarf and cheerful composition. Both legs remain attached, but pedal connections and wing contact with the handlebar are weakly resolved. Wheel alignment and landscape layers are coherent. Clean outlines support the illustration, while flat surfaces and limited lighting keep it short of masterful execution.

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

CategoryKimi K3Muse Spark Open
Task & likeness8.0/107.5/10
Anatomy & construction6.5/105.0/10
Space & placement7.5/106.0/10
Light & reflections5.0/105.0/10
Purposeful detail6.5/106.5/10
Artistry & character6.0/105.5/10
Materials & effects6.0/106.0/10
Visual integrity6.5/107.5/10

Benchmark task

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