Kimi K3.1 Pro 61.1/100Rank 10/47

STEALTHMARK · HEAD TO HEAD
All comparisons ↗Kimi K3.1 Pro leads Muse Spark Open by 12.6 points on StealthMark, 56.7 to 44.1. It leads on 8 of 9 benchmarks, including both games, and Muse Spark Open on 1. Kimi K3.1 Pro scores higher on Newton's Mirror, with its largest category advantage in reflections.
See the difference ↘On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.
BENCHMARK BY BENCHMARK
DATASHEET
Kimi K3.1 Pro scores higher on StealthMark. Muse Spark Open is 2.4× cheaper per output token and runs 3.1× faster in our speed test. Both take about 1M tokens of context.
Full datasheets, every price and sourceKimi K3.1 Pro ↗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.


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.


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


Kimi K3.1 Pro
The settled sphere, separate airborne black paint and crimson-before-cyan interaction are supported, with a modest crimson travel overshoot. A shared downward framing displacement remains after accounting for the square canvas. The principal limitation is the reflection system: sparse sphere copies and generic curved bands omit most of the ordered mirror-room structure. Materials receive a small upward revision because bounded bright images and dark bands visibly establish some polish, while soft shading and bulky paint remain separate weaknesses.
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.
| Category | Kimi K3.1 Pro | Muse Spark Open |
|---|---|---|
| State at 600 ms | 23.5/25 | 14.0/25 |
| Camera and placement | 10.5/15 | 6.0/15 |
| Reflections | 26.0/120 | 8.0/120 |
| Materials and scale | 7.0/10 | 3.5/10 |
| Floor-damage reward | 0.0/10 | 0.0/10 |
A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.
Visual construction and creative interpretation.


Kimi K3.1 Pro
The transformed reflection, attentive pose and constellation anatomy clearly communicate introspection. Purposeful fine details enrich a coherent composition. Tubular limbs, crowded lower-body overlaps, shallow depth and limited cast lighting keep the overall execution within the competent range.
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.
| Category | Kimi K3.1 Pro | Muse Spark Open |
|---|---|---|
| Task & likeness | 8.0/10 | 5.0/10 |
| Anatomy & construction | 5.5/10 | 4.5/10 |
| Space & placement | 6.5/10 | 6.0/10 |
| Light & reflections | 6.5/10 | 5.0/10 |
| Purposeful detail | 7.5/10 | 6.0/10 |
| Artistry & character | 7.0/10 | 5.0/10 |
| Materials & effects | 7.0/10 | 5.0/10 |
| Visual integrity | 7.0/10 | 6.5/10 |
Kimi K3.1 Pro
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.
Precise visual recall and portrait reconstruction.


Kimi K3.1 Pro
A coherent, recognizable interpretation with controlled color and readable landscape layers. Replication is limited by the frontal seated construction, elongated facial proportions and oversized, weakly articulated hands. Smooth shading supplies some volume but little of the reference's subtle expression, fabric structure or atmospheric transitions.
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.
| Category | Kimi K3.1 Pro | Muse Spark Open |
|---|---|---|
| Task & likeness | 5.0/10 | 3.0/10 |
| Anatomy & construction | 5.0/10 | 3.0/10 |
| Space & placement | 5.5/10 | 5.0/10 |
| Light & reflections | 6.0/10 | 4.5/10 |
| Purposeful detail | 5.5/10 | 4.0/10 |
| Artistry & character | 6.0/10 | 3.0/10 |
| Materials & effects | 5.0/10 | 4.0/10 |
| Visual integrity | 6.5/10 | 6.0/10 |
An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.
Creativity, perspective and visual beauty.


Kimi K3.1 Pro
A coherent, playful beach illustration with readable animals, an organized composition and an aligned sunset reflection. Connected silhouettes, sand texture and atmospheric effects demonstrate controlled execution. Simplified joints, flattened foreground viewpoints and inconsistent shadows limit anatomical and spatial credibility.
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.
| Category | Kimi K3.1 Pro | Muse Spark Open |
|---|---|---|
| Task & likeness | 8.5/10 | 8.0/10 |
| Anatomy & construction | 5.5/10 | 6.0/10 |
| Space & placement | 5.5/10 | 6.5/10 |
| Light & reflections | 6.5/10 | 5.5/10 |
| Purposeful detail | 6.5/10 | 6.5/10 |
| Artistry & character | 5.5/10 | 5.5/10 |
| Materials & effects | 6.5/10 | 6.0/10 |
| Visual integrity | 7.5/10 | 8.0/10 |
A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.
Physical reasoning, light and visual reconstruction.


Kimi K3.1 Pro
This benchmark has not been assessed yet.
Muse Spark Open
This benchmark has not been assessed yet.
A plank, computer mouse and blueberry in a steel room test physical stability, spatial relationships, materials and lighting.
Scene composition and interacting subjects.


Kimi K3.1 Pro
The additional comparisons support retaining the assessment. Readable steering, shaped animal contours and purposeful details coexist with simplified joints, a frontal passenger whose seated weight is weakly conveyed, and limited physical lighting. The angled craft establishes more depth than the riding pose resolves.
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.
| Category | Kimi K3.1 Pro | Muse Spark Open |
|---|---|---|
| Task & likeness | 7.0/10 | 4.0/10 |
| Anatomy & construction | 5.5/10 | 3.0/10 |
| Space & placement | 6.0/10 | 6.0/10 |
| Light & reflections | 5.5/10 | 4.5/10 |
| Purposeful detail | 7.0/10 | 7.0/10 |
| Artistry & character | 6.0/10 | 3.5/10 |
| Materials & effects | 6.0/10 | 5.0/10 |
| Visual integrity | 7.0/10 | 5.0/10 |
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.
Subject construction and spatial relationships.


Kimi K3.1 Pro
A characterful coastal illustration with controlled contours and varied feather, accessory and bicycle detail. Layered scenery and subtle shading enrich the presentation. Soft leg articulation, unresolved riding contacts, shallow depth and generalized lighting limit physical precision.
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.
| Category | Kimi K3.1 Pro | Muse Spark Open |
|---|---|---|
| Task & likeness | 8.5/10 | 7.5/10 |
| Anatomy & construction | 7.5/10 | 5.0/10 |
| Space & placement | 6.5/10 | 6.0/10 |
| Light & reflections | 6.5/10 | 5.0/10 |
| Purposeful detail | 7.5/10 | 6.5/10 |
| Artistry & character | 7.5/10 | 5.5/10 |
| Materials & effects | 6.5/10 | 6.0/10 |
| Visual integrity | 7.5/10 | 7.5/10 |
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.