Claude Sonnet 5.5 59.6/100Rank 11/47

STEALTHMARK · HEAD TO HEAD
All comparisons ↗Claude Sonnet 5.5 leads Iceman Contributor by 51.0 points on StealthMark, 70.2 to 19.2. It leads on all 9 benchmarks. Claude Sonnet 5.5 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
Claude Sonnet 5.5 scores higher on StealthMark and runs 5.4× faster in our speed test.
Full datasheets, every price and sourceClaude Sonnet 5.5 ↗
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 ↗


Claude Sonnet 5.5
The near-field silhouettes, broad perspective and paint contact order are recognizable. Missing outer chains, truncated repetitions and absent ordered imagery within the main and reflected spheres substantially limit the reflection system. Sparse spherical highlights leave much of the curved room and emitter mapping unsupported, despite some plausible planar light sequences.
Iceman Contributor
The image provides limited evidence through rounded volume, faint wall strips and floor echoes. Its main sphere is small and low, the paint beads do not establish the required interaction history, and most of the defining mirror structure is missing.
| Category | Claude Sonnet 5.5 | Iceman Contributor |
|---|---|---|
| State at 600 ms | 24.0/25 | 0.5/25 |
| Camera and placement | 15.0/15 | 2.5/15 |
| Reflections | 35.0/120 | 7.5/120 |
| Materials and scale | 10.0/10 | 3.0/10 |
| 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.


Claude Sonnet 5.5
The centered coral squid has a friendly, composed expression and a balanced flower-like silhouette. Eight thick arms and two slender tentacles remain visibly connected, with no inverted parts. The mantle is elongated rather than compact, and the arm spacing is uneven. Soft shading gives volume, but dense stippling weakens the requested smooth matte finish; the broad background halo makes depth less precise.
Iceman Contributor
The crystal crown, cyan eyes and blue faceting communicate an icy fantasy character. Anatomical readability is substantially weaker: the ringed torso, crowded facial construction and fingerless appendages do not resolve the requested childlike crouch or pouncing gesture. Sparse surface detail and shallow shading further limit the result.
| Category | Claude Sonnet 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 8.0/10 | 4.0/10 |
| Anatomy & construction | 8.0/10 | 3.0/10 |
| Space & placement | 8.0/10 | 4.0/10 |
| Light & reflections | 7.5/10 | 4.5/10 |
| Purposeful detail | 8.0/10 | 4.0/10 |
| Artistry & character | 8.0/10 | 4.5/10 |
| Materials & effects | 8.0/10 | 4.5/10 |
| Visual integrity | 8.5/10 | 4.0/10 |
Claude Sonnet 5.5
A coral squid with spreading arms tests connected anatomy, balanced composition and soft surface shading.
Iceman Contributor
Character scenes test expression, anatomy, materials and coherent visual construction.
Precise visual recall and portrait reconstruction.


Claude Sonnet 5.5
The crossed hands, dark dress, restrained smile and winding landscape clearly recall the Mona Lisa. Replication is limited by the frontal symmetry, wide eyes, elongated neck and flattened fingers. Soft facial shading provides volume, but heavy darkness and pervasive crackle obscure forms. The composition is coherent; the landscape and fabric remain visibly schematic.
Iceman Contributor
The portrait retains a dark silhouette against an earthy landscape, but replication is weak. The frontal body, elongated facial proportions and undifferentiated hands lose the reference's defining pose and likeness. Basic gradients and layered hills provide some coherence, with little anatomical or painterly detail.
| Category | Claude Sonnet 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 6.5/10 | 1.5/10 |
| Anatomy & construction | 5.0/10 | 1.5/10 |
| Space & placement | 6.0/10 | 2.5/10 |
| Light & reflections | 6.5/10 | 2.0/10 |
| Purposeful detail | 6.0/10 | 2.0/10 |
| Artistry & character | 6.5/10 | 2.0/10 |
| Materials & effects | 6.0/10 | 2.0/10 |
| Visual integrity | 6.5/10 | 3.0/10 |
An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.
Creativity, perspective and visual beauty.


Claude Sonnet 5.5
A richly designed beach illustration combines radiant sunset bands, intricate palm fans and playful silhouettes within a cohesive purple, coral and turquoise palette. Carefully varied accessories reward close inspection, while overlapping foreground forms and shoreline layers organize the abundant activity. Dense palm strokes compete with focal subjects; animal anatomy, relative scales and reflected silhouettes remain simplified.
Iceman Contributor
A coherent sunset beach with recognizable animals, playful details and effective palm framing. Connected silhouettes and layered scenery support modest construction and placement credit. Jointless figures, limited foreshortening and an inadequately separated sun and reflection keep the execution basic despite its attractive color.
| Category | Claude Sonnet 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 9.0/10 | 7.0/10 |
| Anatomy & construction | 8.0/10 | 3.5/10 |
| Space & placement | 8.5/10 | 6.0/10 |
| Light & reflections | 8.5/10 | 4.0/10 |
| Purposeful detail | 9.5/10 | 5.5/10 |
| Artistry & character | 9.5/10 | 3.5/10 |
| Materials & effects | 8.5/10 | 4.5/10 |
| Visual integrity | 8.0/10 | 5.0/10 |
A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.
Physical reasoning, light and visual reconstruction.


Claude Sonnet 5.5
This benchmark has not been assessed yet.
Iceman Contributor
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.


Claude Sonnet 5.5
The raccoon clearly rides on the dog's back while the dog grips the jet ski controls. Expressive faces, vivid colors and a sweeping wake make the scene appealing. Visible limbs connect coherently, but overlapping steering paws and an indistinct control mounting weaken construction. Flat character lighting and simplified water limit depth and material realism.
Iceman Contributor
The sunset palette and red hull establish an appealing setting, but the central interaction remains unresolved. Overlapping bodies obscure the dog, supported seating is unclear, and no readable paw-to-control grip demonstrates steering. Simple construction, weak environmental lighting and loosely described spray limit depth and finish.
| Category | Claude Sonnet 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 8.5/10 | 2.0/10 |
| Anatomy & construction | 7.0/10 | 3.0/10 |
| Space & placement | 8.0/10 | 3.0/10 |
| Light & reflections | 6.5/10 | 4.0/10 |
| Purposeful detail | 8.0/10 | 3.5/10 |
| Artistry & character | 7.0/10 | 2.5/10 |
| Materials & effects | 7.5/10 | 4.0/10 |
| Visual integrity | 8.0/10 | 2.5/10 |
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.


Claude Sonnet 5.5
The pelican is immediately recognizable, with an expressive face, generous bill and appealing cycling pose. Spokes, chain, feathers and scarf provide purposeful detail. The bicycle largely holds together, though overlapping angular legs obscure the far foot’s pedal contact. Clean outlines and balanced composition succeed; flat surfaces and limited directional lighting constrain depth.
Iceman Contributor
A recognizable pelican and bicycle sit within an appealing sunset composition. Feather contours, bill shape and atmospheric colour provide character, but disconnected-looking leg origins, unclear pedal contact and unresolved steering weaken the central riding action. Consistent wheel alignment establishes a side view without resolving the rider's support.
| Category | Claude Sonnet 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 9.0/10 | 4.0/10 |
| Anatomy & construction | 7.5/10 | 3.5/10 |
| Space & placement | 7.5/10 | 3.5/10 |
| Light & reflections | 6.5/10 | 5.0/10 |
| Purposeful detail | 8.0/10 | 4.5/10 |
| Artistry & character | 7.5/10 | 3.5/10 |
| Materials & effects | 6.5/10 | 4.0/10 |
| Visual integrity | 8.0/10 | 3.0/10 |
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.