STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Kimi K3 vs Step 5 Preview

Kimi K3 leads Step 5 Preview by 11.6 points on StealthMark, 50.6 to 39.0. It leads on 8 of 9 benchmarks, including both games, and Step 5 Preview on 1. Kimi K3 scores higher on Beach, with its largest category advantage in artistry & character.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

50.6/100Overall rank 15/53
39.0/100Overall rank 36/53

General Intelligence

44.4/100
37.1/100

Visual Intelligence

61.4/100
41.9/100

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

Open or local

Open modelKimi K3 License

BENCHMARK BY BENCHMARK

Where each model leads

  • Kimi K3
  • Step 5 Preview
  • Other models
  • Median

DATASHEET

Specs and pricing

Both take about 1M tokens of context.

  • Kimi K3
  • Step 5 Preview
  • Other models
  • Median
PricePer 1M output tokens, input below
Kimi K3: $10.80$0.24 inputStep 5 Preview: No list price
Context windowTokens per request, max output below
Kimi K3: 1MTied1M max outputStep 5 Preview: 1MTied
Output speedTokens per second, our measurement
Kimi K3: 115tokens/sStep 5 Preview: Not measured
SizeTotal and active parameters
Kimi K3: 2.8T104B activeStep 5 Preview: 600B27B active
Developer
Moonshot AIStepFun
Released
16 Jul 2026Not published
Origin
ChinaNot published
Input → output
Text, image → textText, image, video → text
Architecture
Mixture-of-Experts with KDA + Gated MLA attention, 896 experts and native vision encoderSparse mixture-of-experts; 92 layers (88 MoE), 352 routed experts with 8 selected per token plus a shared expert; grouped-query attention with 512-token sliding windows and full attention every fourth layer; 3 multi-token-prediction layers; vision tower for image and video input

Full datasheets, every price and sourceKimi K3 ↗Step 5 Preview ↗

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 16/49

Survived 0 of 3
Foresight: complete playing field
Level 311 ptsTurn 17 / 20

Step 5 Preview 59.9/100Rank 42/491 of 3 levels

1 of 3 played
Foresight: complete playing field
Level 122 ptsTurn 28 / 28

Points per level

LevelKimi K3Step 5 Preview
Level 1Second Thoughts
17 ptsOut of lives
22 ptsSurvived
Level 2Pressure Pot
10 ptsOut of lives
Pending
Level 3Hide or Flight
11 ptsOut of lives
Pending

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 22/50

Cleared 3 of 5
Latch: complete playing field
Level 514.2 ptsTurn 4 / 40

Step 5 Preview 40.7/100Rank 28/50

Cleared 4 of 5
Latch: complete playing field
Level 515 ptsTurn 35 / 40

Points per level

LevelKimi K3Step 5 Preview
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.6 ptsCleared
9 ptsCleared
Level 3Relay vault
18.2 ptsClearedFinished early · 3 beacons left
18.6 ptsCleared
Level 4Passing bay
14.2 ptsFinished early
15.6 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
14.2 ptsFinished early
15 ptsFinished early

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.

Step 5 Preview

The main sphere, airborne black and small colored features occupy broadly appropriate positions. Most of the defining mirror system is absent, and paint interaction remains only partially supported. The small paint features do not visibly establish a separate volume-scale violation.

Score breakdown

CategoryKimi K3Step 5 Preview
State at 600 ms18.0/2520.0/25
Camera and placement8.0/1513.5/15
Reflections24.0/12020.0/120
Materials and scale6.5/107.0/10
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.

Step 5 Preview

A charming diagonal climber and warm palette communicate the central idea. Simple rounded construction, crowded limb counting, uncertain footholds and an unattached upper shelf limit its physical coherence. Growth bands and the yarn trail add specificity, but the requested material distinctions and unravelled bootie remain underdeveloped.

Score breakdown

CategoryKimi K3Step 5 Preview
Task & likeness9.0/106.0/10
Anatomy & construction7.0/104.5/10
Space & placement8.0/105.0/10
Light & reflections7.5/105.5/10
Purposeful detail8.0/105.5/10
Artistry & character8.5/105.0/10
Materials & effects7.5/106.0/10
Visual integrity8.0/105.0/10

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.

Step 5 Preview

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

Mona Lisa

Same 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.

Step 5 Preview

A recognizable, coherent simplification with purposeful facial contours and differentiated fingers. These provide more construction and detail than the broad silhouette alone suggests. The oversized face, frontal seated pose, unresolved wrists and sparse landscape still substantially limit likeness, depth and finish.

Score breakdown

CategoryKimi K3Step 5 Preview
Task & likeness4.5/104.0/10
Anatomy & construction3.5/104.0/10
Space & placement4.5/104.0/10
Light & reflections4.5/103.5/10
Purposeful detail4.0/104.0/10
Artistry & character4.5/104.0/10
Materials & effects4.5/103.0/10
Visual integrity5.0/103.5/10

Benchmark task

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

Beach

Same 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.

Step 5 Preview

A recognizable sunset beach with clear warm-cool contrast and playful accessories. Basic animal construction, shallow foreground placement and schematic reflections limit spatial and physical credibility. Sparse descriptive detail and abruptly ended sky bands constrain the finish.

Score breakdown

CategoryKimi K3Step 5 Preview
Task & likeness8.5/104.0/10
Anatomy & construction7.0/103.0/10
Space & placement7.0/103.5/10
Light & reflections6.5/103.5/10
Purposeful detail8.5/103.0/10
Artistry & character8.5/103.0/10
Materials & effects6.5/103.5/10
Visual integrity7.0/104.0/10

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.

Step 5 Preview

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

Same 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.

Step 5 Preview

Recognizable animals, a bright palette and identifying accessories support a basic cartoon. Primitive anatomy, partial seated support, unresolved steering and weak hull-water contact limit the central action. Lighting and spray provide atmosphere without establishing convincing physical depth.

Score breakdown

CategoryKimi K3Step 5 Preview
Task & likeness8.0/104.0/10
Anatomy & construction6.5/104.5/10
Space & placement7.5/103.0/10
Light & reflections7.0/103.5/10
Purposeful detail7.5/104.0/10
Artistry & character6.0/103.5/10
Materials & effects7.5/103.0/10
Visual integrity7.0/103.0/10

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

Same 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.

Step 5 Preview

The pelican and bicycle are recognizable, with a pleasant palette and basic diffuse shading. The riding relationship fails physically: the bird is unsupported, the front wheel is unmounted, and pedalling is unresolved. Simple geometric construction and sparse material treatment further limit the drawing.

Score breakdown

CategoryKimi K3Step 5 Preview
Task & likeness8.0/103.0/10
Anatomy & construction6.5/103.0/10
Space & placement7.5/103.0/10
Light & reflections5.0/103.0/10
Purposeful detail6.5/104.0/10
Artistry & character6.0/103.0/10
Materials & effects6.0/103.0/10
Visual integrity6.5/102.0/10

Benchmark task

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