STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-5.6 Terra vs Iceman Contributor

GPT-5.6 Terra leads Iceman Contributor by 26.6 points on StealthMark, 45.8 to 19.2. It leads on all 9 benchmarks. GPT-5.6 Terra scores higher on Newton's Mirror, with its largest category advantage in state at 600 ms.

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All results ↗
Model guide ↗

Overall StealthMark

45.8/100Overall rank 25/53
19.2/100Overall rank 47/53

General Intelligence

41.9/100
11.7/100

Visual Intelligence

52.7/100
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

  • GPT-5.6 Terra

Open or local

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-5.6 Terra
  • Iceman Contributor
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-5.6 Terra scores higher on StealthMark and runs 2.2× faster in our speed test.

  • GPT-5.6 Terra
  • Iceman Contributor
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-5.6 Terra: $12$2 inputIceman Contributor: No list price
Context windowTokens per request, max output below
GPT-5.6 Terra: 1.05M128K max outputIceman Contributor: Not published
Output speedTokens per second, our measurement
GPT-5.6 Terra: 1022.2× fastertokens/sIceman Contributor: 46tokens/s
Developer
OpenAINot published
Released
9 Jul 2026Not published
Origin
United StatesNot published
Input → output
Text, image → textNot published

Full datasheets, every price and sourceGPT-5.6 Terra ↗

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.

GPT-5.6 Terra 30.1/100Rank 31/47

Survived 0 of 3
Foresight: complete playing field
Level 36 ptsTurn 7 / 20

Iceman Contributor 3.2/100Rank 47/47

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

Points per level

LevelGPT-5.6 TerraIceman Contributor
Level 1Second Thoughts
5 ptsOut of lives
0 ptsOut of lives
Level 2Pressure Pot
9 ptsOut of lives
3 ptsOut of lives
Level 3Hide or Flight
6 ptsOut of lives
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.

GPT-5.6 Terra 80.0/100Rank 9/48

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

LevelGPT-5.6 TerraIceman Contributor
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.6 ptsCleared
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

GPT-5.6 Terra

The real sphere and airborne black blob are substantially too low in the complete frame after accounting for aspect ratio. The first wall and floor reflections have incompatible placement, relative size or silhouette. Both lateral regions lack the references' receding lane-and-chain organization. The few recognizable mirror images provide limited optical structure. The main, side and floor spheres replace nested mirror imagery with smooth bands, while sparse planar light patches and broad spherical highlights fail to establish coherent repeated emitter mapping.

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

CategoryGPT-5.6 TerraIceman Contributor
State at 600 ms24.0/250.5/25
Camera and placement6.0/152.5/15
Reflections7.0/1207.5/120
Materials and scale5.5/103.0/10
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

GPT-5.6 Terra

Six ivory heads and rounded lobes create a striking radial emblem around a clear hexagonal opening. Soft shading gives the bodies volume, but abrupt rectangular and diagonal band endings make the continuous alternating weave ambiguous. Repetitive scale lines and simplified faces convey an ornamental serpent more convincingly than living anatomy.

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

CategoryGPT-5.6 TerraIceman Contributor
Task & likeness7.5/104.0/10
Anatomy & construction5.5/103.0/10
Space & placement7.0/104.0/10
Light & reflections7.5/104.5/10
Purposeful detail6.5/104.0/10
Artistry & character5.5/104.5/10
Materials & effects6.5/104.5/10
Visual integrity5.0/104.0/10

Benchmark task

GPT-5.6 Terra

A pale serpent woven into an interlocking knot tests connected anatomy, repeated structure and readable overlaps. Organic surface detail must work with the overall geometry.

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

GPT-5.6 Terra

The dark clothing, central portrait and restrained smile evoke the Mona Lisa, but replication is limited by the broad face, elongated neck, nearly frontal pose and indistinct landscape. Soft gradients give the face some volume. Crossed arms become rounded masses without readable fingers or wrists, and the expression lacks the original's subtlety. Clean framing and curves support an otherwise basic, uneven portrait.

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

CategoryGPT-5.6 TerraIceman Contributor
Task & likeness4.0/101.5/10
Anatomy & construction3.0/101.5/10
Space & placement4.5/102.5/10
Light & reflections5.0/102.0/10
Purposeful detail4.0/102.0/10
Artistry & character4.0/102.0/10
Materials & effects4.0/102.0/10
Visual integrity6.0/103.0/10

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

GPT-5.6 Terra

Warm sunset gradients, framing palms and colorful beach activities create an appealing scene. Animals, birds and a sun reflection fulfill the brief. The dog and turtle remain schematic, foreground depth is shallow, and the reflection forms rigid bands. Clean silhouettes and readable accessories support a competent illustration, but limited anatomy, material variation and lighting keep it below exceptional.

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

CategoryGPT-5.6 TerraIceman Contributor
Task & likeness7.5/107.0/10
Anatomy & construction5.0/103.5/10
Space & placement6.0/106.0/10
Light & reflections5.0/104.0/10
Purposeful detail6.5/105.5/10
Artistry & character5.0/103.5/10
Materials & effects5.5/104.5/10
Visual integrity5.0/105.0/10

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

GPT-5.6 Terra

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

GPT-5.6 Terra

Expressive faces, a recognizable raccoon perched on the dog, and a sweeping wake make an appealing cartoon. The principal weakness is the steering interaction: the dog's paw sits beside the control assembly without a convincing handlebar grip. Bold outlines and coherent layering provide polish, while simplified shading, compressed seating geometry and angular splashes limit depth and physical credibility.

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

CategoryGPT-5.6 TerraIceman Contributor
Task & likeness7.5/102.0/10
Anatomy & construction5.0/103.0/10
Space & placement7.0/103.0/10
Light & reflections6.0/104.0/10
Purposeful detail7.0/103.5/10
Artistry & character5.0/102.5/10
Materials & effects7.0/104.0/10
Visual integrity7.5/102.5/10

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

GPT-5.6 Terra

The oversized bill, expressive eye and balanced twilight palette make the cyclist immediately readable. Clean contours and wheel details support the illustration, but the rabbit-like head tufts weaken pelican likeness. The wing does not clearly grip the handlebar, pedal contact is uneven, and the drivetrain is incomplete. Lighting remains mostly decorative.

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

CategoryGPT-5.6 TerraIceman Contributor
Task & likeness6.0/104.0/10
Anatomy & construction6.0/103.5/10
Space & placement7.0/103.5/10
Light & reflections6.5/105.0/10
Purposeful detail7.0/104.5/10
Artistry & character6.5/103.5/10
Materials & effects6.5/104.0/10
Visual integrity7.0/103.0/10

Benchmark task

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