Gemini 3.8 Flash 45.4/100Rank 20/47

STEALTHMARK · HEAD TO HEAD
All comparisons ↗Kimi K3.1 Pro leads Gemini 3.8 Flash by 8.8 points on StealthMark, 56.7 to 47.9. It leads on 6 of 9 benchmarks, including both games, and Gemini 3.8 Flash on 3. 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
Gemini 3.8 Flash is 2.7× cheaper per output token and runs 46% faster in our speed test. Kimi K3.1 Pro scores higher on StealthMark. Both take about 1M tokens of context.
Full datasheets, every price and sourceGemini 3.8 Flash ↗Kimi K3.1 Pro ↗
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 ↗


Gemini 3.8 Flash
Crimson is carried well down the camera-facing surface, supporting its earlier interaction. The depiction remains highly simplified, with imperfect material rendering. Isolated wall and floor images and a few highlights provide scant reflective evidence; displaced first reflections, missing receding chains and absent nested sphere and emitter imagery leave the room's optical structure largely unsupported.
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.
| Category | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| State at 600 ms | 22.5/25 | 23.5/25 |
| Camera and placement | 11.0/15 | 10.5/15 |
| Reflections | 4.5/120 | 26.0/120 |
| Materials and scale | 7.0/10 | 7.0/10 |
| 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.


Gemini 3.8 Flash
The dominant four-point silhouette, luminous color progression, raised brows and enormous grin closely fulfill the brief. Attached, secondary limbs support the exuberant expression. Clean facial drawing and glossy eyes give strong character, while shallow depth, minimally articulated extremities and visible steps in the outer glow limit refinement.
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.
| Category | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Task & likeness | 8.0/10 | 8.0/10 |
| Anatomy & construction | 6.0/10 | 5.5/10 |
| Space & placement | 6.5/10 | 6.5/10 |
| Light & reflections | 7.0/10 | 6.5/10 |
| Purposeful detail | 5.0/10 | 7.5/10 |
| Artistry & character | 3.5/10 | 7.0/10 |
| Materials & effects | 5.0/10 | 7.0/10 |
| Visual integrity | 6.5/10 | 7.0/10 |
Gemini 3.8 Flash
A luminous star-shaped creature tests expressive features, a clear silhouette and smooth colour transitions.
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.
Precise visual recall and portrait reconstruction.


Gemini 3.8 Flash
The dark clothing, overlapping hands and hazy landscape make the Mona Lisa reference recognizable. Replication is limited by the frontal, elongated face, heavy mouth and chin, and poorly resolved hands, wrists and forearm. Soft shading gives some volume, but muddy transitions, blunt landscape shapes and rigid facial modeling weaken the portrait’s expression and painterly character.
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.
| Category | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Task & likeness | 3.0/10 | 5.0/10 |
| Anatomy & construction | 2.0/10 | 5.0/10 |
| Space & placement | 3.5/10 | 5.5/10 |
| Light & reflections | 3.0/10 | 6.0/10 |
| Purposeful detail | 5.0/10 | 5.5/10 |
| Artistry & character | 3.0/10 | 6.0/10 |
| Materials & effects | 5.0/10 | 5.0/10 |
| Visual integrity | 1.0/10 | 6.5/10 |
An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.
Creativity, perspective and visual beauty.


Gemini 3.8 Flash
A vivid purple-and-gold sunset anchors an appealing beach composition with dolphins, birds, a turtle and playful accessories. Palm silhouettes frame the bright reflection effectively. Sparse animal anatomy, wirelike palm foliage, conspicuously regular reflection bands and limited surface texture keep the execution below exceptional.
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.
| Category | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Task & likeness | 9.0/10 | 8.5/10 |
| Anatomy & construction | 7.0/10 | 5.5/10 |
| Space & placement | 7.0/10 | 5.5/10 |
| Light & reflections | 8.0/10 | 6.5/10 |
| Purposeful detail | 7.0/10 | 6.5/10 |
| Artistry & character | 7.0/10 | 5.5/10 |
| Materials & effects | 7.0/10 | 6.5/10 |
| Visual integrity | 8.0/10 | 7.5/10 |
A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.
Physical reasoning, light and visual reconstruction.


Gemini 3.8 Flash
This benchmark has not been assessed yet.
Kimi K3.1 Pro
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.


Gemini 3.8 Flash
Expressive animals, a bold diagonal hull and sweeping spray create an appealing action scene. The raccoon's support on the dog's back is unclear, and the dog lacks a readable paw-to-control grip and connected steering assembly. Clean graphic shapes and lively accessories are stronger than the anatomical construction. Sunset illumination and reflections remain largely decorative.
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.
| Category | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Task & likeness | 7.0/10 | 7.0/10 |
| Anatomy & construction | 6.0/10 | 5.5/10 |
| Space & placement | 7.0/10 | 6.0/10 |
| Light & reflections | 6.5/10 | 5.5/10 |
| Purposeful detail | 7.5/10 | 7.0/10 |
| Artistry & character | 7.5/10 | 6.0/10 |
| Materials & effects | 7.5/10 | 6.0/10 |
| Visual integrity | 7.5/10 | 7.0/10 |
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.


Gemini 3.8 Flash
The pelican’s enormous bill, lively feathers and orange bicycle create a clear, appealing composition. Basket contents, spokes and facial details reward inspection. Both legs connect to the body, but foot-to-pedal placement and wing-to-handlebar contact are ambiguous. Bicycle mechanics and lighting remain schematic, limiting an otherwise polished illustration.
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.
| Category | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Task & likeness | 9.0/10 | 8.5/10 |
| Anatomy & construction | 7.5/10 | 7.5/10 |
| Space & placement | 7.5/10 | 6.5/10 |
| Light & reflections | 7.0/10 | 6.5/10 |
| Purposeful detail | 8.5/10 | 7.5/10 |
| Artistry & character | 8.0/10 | 7.5/10 |
| Materials & effects | 7.0/10 | 6.5/10 |
| Visual integrity | 8.0/10 | 7.5/10 |
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.