Claude Opus 5.5 66.3/100Rank 5/52

STEALTHMARK · HEAD TO HEAD
All comparisons ↗Claude Opus 5.5 leads Crouton Alpha by 24.6 points on StealthMark, 72.6 to 48.0. It leads on all 9 benchmarks. Claude Opus 5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections.
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BENCHMARK BY BENCHMARK
DATASHEET
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.
Crouton Alpha
The artwork establishes approximate central placement, a separate airborne black blob, and basic wall and floor sphere images. Its defining weaknesses are the largely absent recursive reflection system, missing emitter mappings, satin steel appearance and unresolved paint interaction. The black lateral wedges do not establish a separate viewport, and the hidden floor contact does not establish a gap. The category values remain unchanged.
| Category | Claude Opus 5.5 | Crouton Alpha |
|---|---|---|
| State at 600 ms | 24.0/25 | 19.0/25 |
| Camera and placement | 15.0/15 | 11.0/15 |
| Reflections | 55.0/120 | 21.5/120 |
| Materials and scale | 9.0/10 | 6.0/10 |
| 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.
Crouton Alpha
A cheerful, readable cartoon captures the crouton's signature expression and many specific accessories. Coherent cube geometry and foreground foreshortening support the selfie. Simple construction and flat material treatment limit its sophistication, while the tipping raft, advancing soup and unnoticed soaking remain insufficiently clear.
| Category | Claude Opus 5.5 | Crouton Alpha |
|---|---|---|
| Task & likeness | 8.0/10 | 6.5/10 |
| Anatomy & construction | 7.5/10 | 5.5/10 |
| Space & placement | 8.0/10 | 6.5/10 |
| Light & reflections | 7.5/10 | 5.5/10 |
| Purposeful detail | 7.0/10 | 7.0/10 |
| Artistry & character | 7.0/10 | 5.0/10 |
| Materials & effects | 7.0/10 | 5.5/10 |
| Visual integrity | 8.5/10 | 7.5/10 |
Claude Opus 5.5
A coral squid with spreading arms tests connected anatomy, balanced composition and soft surface shading.
Crouton Alpha
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.
Crouton Alpha
A recognizable, coherent simplification with readable eyes, a restrained smile and modest facial volume. Frontal symmetry, an oversized head, capsule-like hands and geometric scenery substantially limit likeness, anatomy and depth. Clean contours preserve basic integrity but do not establish sophisticated construction or finish.
| Category | Claude Opus 5.5 | Crouton Alpha |
|---|---|---|
| Task & likeness | 6.5/10 | 4.5/10 |
| Anatomy & construction | 5.5/10 | 4.0/10 |
| Space & placement | 6.5/10 | 4.5/10 |
| Light & reflections | 6.5/10 | 5.0/10 |
| Purposeful detail | 6.5/10 | 4.0/10 |
| Artistry & character | 6.0/10 | 4.5/10 |
| Materials & effects | 7.0/10 | 4.0/10 |
| Visual integrity | 7.0/10 | 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.


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.
Crouton Alpha
A colorful, readable sunset beach scene with playful subjects and a clear central reflection. Purposeful equipment and animal details reward inspection, and the principal attachments remain intact. Basic geometric anatomy, mixed viewpoints and sparse directional shadows limit its construction and depth; smooth gradients provide atmosphere with little material differentiation.
| Category | Claude Opus 5.5 | Crouton Alpha |
|---|---|---|
| Task & likeness | 8.5/10 | 8.5/10 |
| Anatomy & construction | 7.5/10 | 5.0/10 |
| Space & placement | 7.0/10 | 5.5/10 |
| Light & reflections | 7.5/10 | 5.5/10 |
| Purposeful detail | 7.5/10 | 7.0/10 |
| Artistry & character | 8.0/10 | 5.0/10 |
| Materials & effects | 6.5/10 | 5.5/10 |
| Visual integrity | 8.0/10 | 7.0/10 |
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.
Crouton Alpha
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.
Crouton Alpha
A readable cartoon with expressive faces, purposeful markings and clear water motion. Hull shading and an underside shadow establish modest depth. The dog contacts the controls, but the raccoon's frontal pose leaves its seated weight unresolved. Simple anatomy and limited shared perspective constrain the drawing.
| Category | Claude Opus 5.5 | Crouton Alpha |
|---|---|---|
| Task & likeness | 8.5/10 | 7.0/10 |
| Anatomy & construction | 7.5/10 | 5.0/10 |
| Space & placement | 7.5/10 | 6.0/10 |
| Light & reflections | 6.0/10 | 6.0/10 |
| Purposeful detail | 8.5/10 | 6.5/10 |
| Artistry & character | 7.0/10 | 5.0/10 |
| Materials & effects | 7.0/10 | 5.5/10 |
| Visual integrity | 8.0/10 | 6.0/10 |
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.


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.
Crouton Alpha
A recognizable, expressive pelican cyclist with purposeful feather and bicycle detail. Readable steering reach, connected machinery and modest body shading earn additional credit. Jointless legs, uncertain pedal engagement and unclear seated support keep the central action only partially resolved; shallow space and simple materials further limit the illustration.
| Category | Claude Opus 5.5 | Crouton Alpha |
|---|---|---|
| Task & likeness | 8.5/10 | 7.0/10 |
| Anatomy & construction | 8.0/10 | 5.0/10 |
| Space & placement | 7.0/10 | 5.5/10 |
| Light & reflections | 6.0/10 | 5.5/10 |
| Purposeful detail | 8.0/10 | 6.5/10 |
| Artistry & character | 7.5/10 | 5.5/10 |
| Materials & effects | 6.0/10 | 5.0/10 |
| Visual integrity | 8.5/10 | 6.0/10 |
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.