Claude Opus 5.5 66.3/100Rank 5/47

STEALTHMARK · HEAD TO HEAD
All comparisons ↗Claude Opus 5.5 leads Iceman Contributor by 53.4 points on StealthMark, 72.6 to 19.2. It leads on all 9 benchmarks. Claude Opus 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 Opus 5.5 scores higher on StealthMark and runs 3.6× faster in our speed test.
Full datasheets, every price and sourceClaude Opus 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 Opus 5.5
Open lateral sightlines, first reflected silhouettes and near-field planar panel placement are convincing. Missing outer chains, truncated repetitions and absent nested spherical room and emitter imagery remain the main weaknesses.
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 Opus 5.5 | Iceman Contributor |
|---|---|---|
| State at 600 ms | 24.0/25 | 0.5/25 |
| Camera and placement | 15.0/15 | 2.5/15 |
| Reflections | 55.0/120 | 7.5/120 |
| Materials and scale | 9.0/10 | 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 Opus 5.5
The centered coral squid has a friendly, restrained expression and a balanced radial silhouette within a cream arch. Smooth curves and soft shading give it an appealing matte finish. The mantle is more elongated than compact, the upper arms are visually ambiguous, and the two hanging tentacles read somewhat like legs. Clean execution supports a strong stylized illustration.
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 Opus 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 8.0/10 | 4.0/10 |
| Anatomy & construction | 7.5/10 | 3.0/10 |
| Space & placement | 8.0/10 | 4.0/10 |
| Light & reflections | 7.5/10 | 4.5/10 |
| Purposeful detail | 7.0/10 | 4.0/10 |
| Artistry & character | 7.0/10 | 4.5/10 |
| Materials & effects | 7.0/10 | 4.5/10 |
| Visual integrity | 8.5/10 | 4.0/10 |
Claude Opus 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 Opus 5.5
The portrait preserves the recognizable composition, dark veil, folded hands and distant landscape. Replication is limited by the elongated face and neck, conspicuous eyes and simplified smile. Hands remain connected but their rounded fingers and wrists lack convincing anatomy. Restrained colors create cohesion; shallow modeling and pervasive mottling weaken volume and painterly subtlety.
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 Opus 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 6.5/10 | 1.5/10 |
| Anatomy & construction | 5.5/10 | 1.5/10 |
| Space & placement | 6.5/10 | 2.5/10 |
| Light & reflections | 6.5/10 | 2.0/10 |
| Purposeful detail | 6.5/10 | 2.0/10 |
| Artistry & character | 6.0/10 | 2.0/10 |
| Materials & effects | 7.0/10 | 2.0/10 |
| Visual integrity | 7.0/10 | 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 Opus 5.5
A lively, well-composed beach illustration with rich sunset colors, recognizable animals and appealing accessories. The sun reflection establishes a strong central focus. Clean silhouettes and small details reward inspection, though simplified animal construction, uneven contact shadows and mostly flat materials limit depth and realism.
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 Opus 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 8.5/10 | 7.0/10 |
| Anatomy & construction | 7.5/10 | 3.5/10 |
| Space & placement | 7.0/10 | 6.0/10 |
| Light & reflections | 7.5/10 | 4.0/10 |
| Purposeful detail | 7.5/10 | 5.5/10 |
| Artistry & character | 8.0/10 | 3.5/10 |
| Materials & effects | 6.5/10 | 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 Opus 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 Opus 5.5
The masked raccoon clearly rides the dog's back, and the dog's forward paw reaches the steering grip. Expressive faces, vivid colors and sweeping wakes create an appealing illustration. Connected limbs remain schematic, as does the small steering assembly. The broad hull and flat foam weaken water contact; the glowing sun lacks a corresponding reflection or convincing cast shadows.
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 Opus 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 8.5/10 | 2.0/10 |
| Anatomy & construction | 7.5/10 | 3.0/10 |
| Space & placement | 7.5/10 | 3.0/10 |
| Light & reflections | 6.0/10 | 4.0/10 |
| Purposeful detail | 8.5/10 | 3.5/10 |
| Artistry & character | 7.0/10 | 2.5/10 |
| Materials & effects | 7.0/10 | 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 Opus 5.5
The recognizable pelican, orderly bicycle wheels and harmonious sunset create an appealing illustration. Both legs connect to the body and reach pedals; no clear detached or inverted parts appear. Steering contact and seating support are less convincing, while the drivetrain remains schematic. Crisp outlines give a clean finish, but limited shading and flat surfaces leave the scene with modest 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 Opus 5.5 | Iceman Contributor |
|---|---|---|
| Task & likeness | 8.5/10 | 4.0/10 |
| Anatomy & construction | 8.0/10 | 3.5/10 |
| Space & placement | 7.0/10 | 3.5/10 |
| Light & reflections | 6.0/10 | 5.0/10 |
| Purposeful detail | 8.0/10 | 4.5/10 |
| Artistry & character | 7.5/10 | 3.5/10 |
| Materials & effects | 6.0/10 | 4.0/10 |
| Visual integrity | 8.5/10 | 3.0/10 |
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.