STEALTHMARK · HEAD TO HEAD
All comparisons ↗Kolibri-1 vs Step 5 Preview
Step 5 Preview leads Kolibri-1 by 25.4 points on StealthMark, 39.0 to 13.6. It leads on all 7 benchmarks with results for both. Step 5 Preview scores higher on Newton's Mirror, with its largest category advantage in reflections.
See the difference ↘Overall StealthMark
General Intelligence
Visual Intelligence
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
- Kolibri-1Multi-step reasoning not measured
BENCHMARK BY BENCHMARK
Where each model leads
- Kolibri-1
- Step 5 Preview
- Other models
- Median
Games
SVG
DATASHEET
Specs and pricing
Both take about 1M tokens of context.
- Kolibri-1
- Step 5 Preview
- Other models
- Median
- Developer
- Aleph AlphaStepFun
- Released
- 3 Oct 2026Not published
- Origin
- GermanyNot published
- Input → output
- Text → textText, image, video → text
- Architecture
- Mixture-of-Experts with 4:1 sliding-window-attention to global-attention patternSparse 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 sourceKolibri-1 ↗Step 5 Preview ↗
Foresight
Play Foresight yourselfAnticipating 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.
Step 5 Preview 59.9/100Rank 42/491 of 3 levels

Points per level
Latch
Play Latch yourselfCooperative 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.
Kolibri-1No run
Step 5 Preview 40.7/100Rank 28/50

Points per level
Newton's Mirror
Same task instructionsPhysics, perspective and recursive reflections, tested together. Explore the test ↗
Kolibri-1 10.4/100 Rank 47/53

Step 5 Preview 37.9/100 Rank 19/53

The judgment
Kolibri-1
A segmented gray perimeter surrounds a black field containing one large, low-positioned gray sphere and two small colored circles. Rounded volume and restrained paint scale earn partial material credit. The image does not demonstrate the required optical structure, while paint history, airborne black and settled support remain largely unresolved.
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
| Category | Kolibri-1 | Step 5 Preview |
|---|---|---|
| State at 600 ms | 9.5/25 | 20.0/25 |
| Camera and placement | 1.5/15 | 13.5/15 |
| Reflections | 0.0/120 | 20.0/120 |
| Materials and scale | 3.0/10 | 7.0/10 |
| Floor-damage reward | 0.0/10 | 0.0/10 |
Benchmark task
A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.
Selfie
Different task instructionsVisual construction and creative interpretation.
Kolibri-1 22.9/100 Rank 53/53

Step 5 Preview 52.0/100 Rank 40/53

The judgment
Kolibri-1
A restrained ivory, teal and green palette gives the image simple graphic coherence. Execution remains rudimentary: detached oval wings, ambiguous central anatomy and unclear feeding contact prevent a convincing hummingbird scene. The requested feather structure, botanical detail, lighting and enclosing arch are largely unresolved.
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
| Category | Kolibri-1 | Step 5 Preview |
|---|---|---|
| Task & likeness | 2.5/10 | 6.0/10 |
| Anatomy & construction | 2.0/10 | 4.5/10 |
| Space & placement | 3.0/10 | 5.0/10 |
| Light & reflections | 2.0/10 | 5.5/10 |
| Purposeful detail | 1.5/10 | 5.5/10 |
| Artistry & character | 1.5/10 | 5.0/10 |
| Materials & effects | 2.0/10 | 6.0/10 |
| Visual integrity | 5.5/10 | 5.0/10 |
Benchmark task
Kolibri-1
A jewel-coloured hummingbird hovering in flight tests avian anatomy, delicate structure and iridescent surface detail.
Step 5 Preview
Character scenes test expression, anatomy, materials and coherent visual construction.
Mona Lisa
Different task instructionsPrecise visual recall and portrait reconstruction.
Kolibri-1 3.3/100 Rank 51/53

Step 5 Preview 38.4/100 Rank 27/53

The judgment
Kolibri-1
The candidate offers a clean, highly simplified frontal portrait with warm skin and dark hair. Its oversized oval face, schematic features and unresolved body provide little Mona Lisa likeness. Missing crossed hands, clothing detail and landscape remove essential parts of the original composition; smooth gradients supply only limited volume.
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
| Category | Kolibri-1 | Step 5 Preview |
|---|---|---|
| Task & likeness | 0.5/10 | 4.0/10 |
| Anatomy & construction | 0.5/10 | 4.0/10 |
| Space & placement | 0.0/10 | 4.0/10 |
| Light & reflections | 0.0/10 | 3.5/10 |
| Purposeful detail | 0.0/10 | 4.0/10 |
| Artistry & character | 0.5/10 | 4.0/10 |
| Materials & effects | 0.5/10 | 3.0/10 |
| Visual integrity | 0.5/10 | 3.5/10 |
Benchmark task
An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.
Beach
Same task instructionsCreativity, perspective and visual beauty.
Kolibri-1 12.9/100 Rank 52/53

Step 5 Preview 33.5/100 Rank 48/53

The judgment
Kolibri-1
A recognizable sunset beach has an appealing purple-orange gradient and clean geometric edges. Birds and animals remain unresolved, terrain obscures the relationship between shore and water, and reflections are absent. Sparse detail, flat materials and limited activity keep the drawing elementary despite its tidy rendering.
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
| Category | Kolibri-1 | Step 5 Preview |
|---|---|---|
| Task & likeness | 2.5/10 | 4.0/10 |
| Anatomy & construction | 0.5/10 | 3.0/10 |
| Space & placement | 3.0/10 | 3.5/10 |
| Light & reflections | 1.0/10 | 3.5/10 |
| Purposeful detail | 0.5/10 | 3.0/10 |
| Artistry & character | 1.0/10 | 3.0/10 |
| Materials & effects | 0.5/10 | 3.5/10 |
| Visual integrity | 3.0/10 | 4.0/10 |
Benchmark task
A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.
Ground Truth
Same task instructionsPhysical reasoning, light and visual reconstruction.
Kolibri-1 21.2/100 Rank 44/53

Step 5 Preview 33.3/100 Rank 35/53

The judgment
Kolibri-1
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 instructionsScene composition and interacting subjects.
Kolibri-1 10.0/100 Rank 53/53

Step 5 Preview 37.8/100 Rank 44/53

The judgment
Kolibri-1
Clean shapes and a readable coral platform provide basic graphic clarity, but the animal construction remains fragmented. A recognizable raccoon riding the dog's back, connected steering and convincing water contact are not demonstrated. Sparse detail, flat subjects and absent movement effects support retaining the baseline category assessments.
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
| Category | Kolibri-1 | Step 5 Preview |
|---|---|---|
| Task & likeness | 1.5/10 | 4.0/10 |
| Anatomy & construction | 1.0/10 | 4.5/10 |
| Space & placement | 1.0/10 | 3.0/10 |
| Light & reflections | 0.0/10 | 3.5/10 |
| Purposeful detail | 0.5/10 | 4.0/10 |
| Artistry & character | 0.5/10 | 3.5/10 |
| Materials & effects | 0.5/10 | 3.0/10 |
| Visual integrity | 3.5/10 | 3.0/10 |
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 instructionsSubject construction and spatial relationships.
Kolibri-1 17.5/100 Rank 53/53

Step 5 Preview 30.0/100 Rank 51/53

The judgment
Kolibri-1
Clean shapes and aligned wheels establish a readable schematic scene. Pelican likeness, riding support and bicycle mechanics remain substantially unresolved. Sparse detail and flat surfaces limit expression and volume. Strong edge and fill integrity is a separate success and does not repair the construction.
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
| Category | Kolibri-1 | Step 5 Preview |
|---|---|---|
| Task & likeness | 1.5/10 | 3.0/10 |
| Anatomy & construction | 1.5/10 | 3.0/10 |
| Space & placement | 1.5/10 | 3.0/10 |
| Light & reflections | 3.0/10 | 3.0/10 |
| Purposeful detail | 1.5/10 | 4.0/10 |
| Artistry & character | 1.0/10 | 3.0/10 |
| Materials & effects | 1.0/10 | 3.0/10 |
| Visual integrity | 3.5/10 | 2.0/10 |
Benchmark task
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.