STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Claude Sonnet 5.5 vs Iceman Contributor

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.

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All results ↗
Model guide ↗

Overall StealthMark

70.2/100Overall rank 3/53
19.2/100Overall rank 47/53

General Intelligence

67.0/100
11.7/100

Visual Intelligence

76.1/100
31.0/100

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

  • Claude Sonnet 5.5

Open or local

BENCHMARK BY BENCHMARK

Where each model leads

  • Claude Sonnet 5.5
  • Iceman Contributor
  • Other models
  • Median

DATASHEET

Specs and pricing

Claude Sonnet 5.5 scores higher on StealthMark and runs 5.4× faster in our speed test.

  • Claude Sonnet 5.5
  • Iceman Contributor
  • Other models
  • Median
PricePer 1M output tokens, input below
Claude Sonnet 5.5: $10$2 inputIceman Contributor: No list price
Context windowTokens per request, max output below
Claude Sonnet 5.5: 1M128K max outputIceman Contributor: Not published
Output speedTokens per second, our measurement
Claude Sonnet 5.5: 2495.4× fastertokens/sIceman Contributor: 46tokens/s
Developer
AnthropicNot published
Released
28 Sep 2026Not published
Origin
United StatesNot published
Input → output
Text, image → textNot published

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.

Claude Sonnet 5.5 59.6/100Rank 11/47

Survived 2 of 3
Foresight: complete playing field
Level 310 ptsTurn 20 / 20

Iceman Contributor 3.2/100Rank 47/47

Survived 0 of 3
Foresight: complete playing field
Level 31 ptsTurn 7 / 20

Points per level

LevelClaude Sonnet 5.5Iceman Contributor
Level 1Second Thoughts
25 ptsSurvived
0 ptsOut of lives
Level 2Pressure Pot
10 ptsOut of lives
3 ptsOut of lives
Level 3Hide or Flight
10 ptsSurvived
1 ptsOut of lives

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.

Claude Sonnet 5.5 83.9/100Rank 4/48

Cleared 5 of 5
Latch: complete playing field
Level 520.6 ptsTurn 27 / 40

Iceman Contributor 3.6/100Rank 44/48

Cleared 1 of 5
Latch: complete playing field
Level 55 ptsTurn 25 / 40

Points per level

LevelClaude Sonnet 5.5Iceman Contributor
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10 ptsClearedFinished early · 1 beacon left
2.8 ptsFinished early
Level 3Relay vault
19.2 ptsCleared
2.2 ptsFinished early
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
4 ptsFinished early
Level 5Second thoughts
20.6 ptsCleared
5 ptsFinished early

Newton's Mirror

Same task instructions

Physics, perspective and recursive reflections, tested together. Explore the test ↗

The judgment

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.

Score breakdown

CategoryClaude Sonnet 5.5Iceman Contributor
State at 600 ms24.0/250.5/25
Camera and placement15.0/152.5/15
Reflections35.0/1207.5/120
Materials and scale10.0/103.0/10
Floor-damage reward0.0/100.0/10

Benchmark task

A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.

Selfie

Different task instructions

Visual construction and creative interpretation.

The judgment

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.

Score breakdown

CategoryClaude Sonnet 5.5Iceman Contributor
Task & likeness8.0/104.0/10
Anatomy & construction8.0/103.0/10
Space & placement8.0/104.0/10
Light & reflections7.5/104.5/10
Purposeful detail8.0/104.0/10
Artistry & character8.0/104.5/10
Materials & effects8.0/104.5/10
Visual integrity8.5/104.0/10

Benchmark task

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.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

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.

Score breakdown

CategoryClaude Sonnet 5.5Iceman Contributor
Task & likeness6.5/101.5/10
Anatomy & construction5.0/101.5/10
Space & placement6.0/102.5/10
Light & reflections6.5/102.0/10
Purposeful detail6.0/102.0/10
Artistry & character6.5/102.0/10
Materials & effects6.0/102.0/10
Visual integrity6.5/103.0/10

Benchmark task

An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.

Beach

Different task instructions

Creativity, perspective and visual beauty.

The judgment

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.

Score breakdown

CategoryClaude Sonnet 5.5Iceman Contributor
Task & likeness9.0/107.0/10
Anatomy & construction8.0/103.5/10
Space & placement8.5/106.0/10
Light & reflections8.5/104.0/10
Purposeful detail9.5/105.5/10
Artistry & character9.5/103.5/10
Materials & effects8.5/104.5/10
Visual integrity8.0/105.0/10

Benchmark task

A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.

Ground Truth

Different task instructions

Physical reasoning, light and visual reconstruction.

The judgment

Claude Sonnet 5.5

This benchmark has not been assessed yet.

Iceman Contributor

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

Different task instructions

Scene composition and interacting subjects.

The judgment

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.

Score breakdown

CategoryClaude Sonnet 5.5Iceman Contributor
Task & likeness8.5/102.0/10
Anatomy & construction7.0/103.0/10
Space & placement8.0/103.0/10
Light & reflections6.5/104.0/10
Purposeful detail8.0/103.5/10
Artistry & character7.0/102.5/10
Materials & effects7.5/104.0/10
Visual integrity8.0/102.5/10

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

Different task instructions

Subject construction and spatial relationships.

The judgment

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.

Score breakdown

CategoryClaude Sonnet 5.5Iceman Contributor
Task & likeness9.0/104.0/10
Anatomy & construction7.5/103.5/10
Space & placement7.5/103.5/10
Light & reflections6.5/105.0/10
Purposeful detail8.0/104.5/10
Artistry & character7.5/103.5/10
Materials & effects6.5/104.0/10
Visual integrity8.0/103.0/10

Benchmark task

A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.