STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-5.6 Sol vs GPT-6.1 Terra Low

GPT-5.6 Sol leads GPT-6.1 Terra Low by 12.8 points on StealthMark, 54.1 to 41.3. It leads on 8 of 9 benchmarks, including both games, and GPT-6.1 Terra Low on 1. GPT-5.6 Sol scores higher on Ground Truth.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

54.1/100Overall rank 13/55
41.3/100Overall rank 35/55

General Intelligence

51.9/100
34.3/100

Visual Intelligence

58.2/100
53.1/100

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-5.6 Sol
  • GPT-6.1 Terra Low
  • Other models
  • Median

DATASHEET

Specs and pricing

  • GPT-5.6 Sol
  • GPT-6.1 Terra Low
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-5.6 Sol: $20$4 inputGPT-6.1 Terra Low: No list price
Context windowTokens per request, max output below
GPT-5.6 Sol: 1.05M128K max outputGPT-6.1 Terra Low: Not published
Output speedTokens per second, our measurement
GPT-5.6 Sol: 81tokens/sGPT-6.1 Terra Low: Not measured
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 Sol ↗

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 Sol 62.9/100Rank 8/51

Survived 1 of 3
Foresight: complete playing field
Level 311 ptsTurn 17 / 20

GPT-6.1 Terra Low 36.1/100Rank 26/51

Survived 1 of 3
Foresight: complete playing field
Level 39 ptsTurn 20 / 20

Points per level

LevelGPT-5.6 SolGPT-6.1 Terra Low
Level 1Second Thoughts
27 ptsSurvived
4 ptsOut of lives
Level 2Pressure Pot
10 ptsOut of lives
8 ptsOut of lives
Level 3Hide or Flight
11 ptsOut of lives
9 ptsSurvived

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 Sol 83.6/100Rank 5/52

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

GPT-6.1 Terra Low 62.4/100Rank 23/52

Cleared 4 of 5
Latch: complete playing field
Level 520.6 ptsTurn 27 / 40

Points per level

LevelGPT-5.6 SolGPT-6.1 Terra Low
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10.2 ptsClearedFinished early · 1 beacon left
9.2 ptsCleared
Level 3Relay vault
18.8 ptsCleared
18.8 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
10.2 ptsFinished early
Level 5Second thoughts
20.6 ptsCleared
20.6 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

GPT-5.6 Sol

The central sphere and paint ordering are supported, but a frontal, centrally converging chamber replaces the required corner perspective. The first wall and floor images have incorrect placement and scale relationships. Sparse reflection cues remain, while continuous outer chains, open lateral sightlines, dense planar light sequences and curved nested spherical imagery are largely missing.

GPT-6.1 Terra Low

Deformed colored paint and a separate airborne black body establish readable interaction history. Cyan has travelled too far, framing differs substantially, and the mirror system supplies only elementary bands and oval copies. Missing recursive geometry, nested spherical imagery and emitter mapping remain the dominant weaknesses.

Score breakdown

CategoryGPT-5.6 SolGPT-6.1 Terra Low
State at 600 ms23.0/2522.0/25
Camera and placement6.0/154.0/15
Reflections11.0/12010.0/120
Materials and scale7.5/106.0/10
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

Same task instructions

Visual construction and creative interpretation.

The judgment

GPT-5.6 Sol

Six evenly spaced lobes, outward-facing heads and a clear central hexagon establish the requested knot. The ivory silhouette is controlled, but broad crossing bands resemble rigid strips, shading provides limited muscular volume, and repetitive scale lines extend across black loop openings. Small oval heads have readable eyes and mouths but limited anatomical character or moist surface detail.

GPT-6.1 Terra Low

Six attached outward-facing heads, delicate scales and soft ivory shading establish an orderly decorative motif. Separate paddle-shaped bodies replace the required interlocking loops and leave no enclosed central hexagon. Surface detail provides interest, but repeated simple forms, schematic faces and limited anatomical modeling constrain the result.

Score breakdown

CategoryGPT-5.6 SolGPT-6.1 Terra Low
Task & likeness7.5/104.0/10
Anatomy & construction6.0/103.5/10
Space & placement7.0/104.5/10
Light & reflections5.0/105.5/10
Purposeful detail6.0/105.5/10
Artistry & character6.5/105.0/10
Materials & effects4.5/105.5/10
Visual integrity6.0/104.0/10

Benchmark task

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.

Mona Lisa

Same task instructions

Precise visual recall and portrait reconstruction.

The judgment

GPT-5.6 Sol

The crossed hands, dark dress and winding landscape establish the Mona Lisa composition. Replication is limited by enlarged eyes, an elongated face and a more frontal pose. Broad gradients suggest volume, but outlined features and flattened, overlapping fingers weaken the portrait. The frame and restrained palette unify the image; visible grain adds texture without convincing painterly transitions.

GPT-6.1 Terra Low

A recognizable, coherent portrait with purposeful facial detail, warm local volume and layered scenery. The frontal pose, enlarged face, merged hands and shallow clothing construction substantially limit replication and drawing skill. The visible successes support retaining the current assessment.

Score breakdown

CategoryGPT-5.6 SolGPT-6.1 Terra Low
Task & likeness4.5/105.0/10
Anatomy & construction4.0/104.5/10
Space & placement5.5/105.0/10
Light & reflections5.0/106.0/10
Purposeful detail5.0/105.0/10
Artistry & character4.5/105.5/10
Materials & effects5.5/105.0/10
Visual integrity6.5/106.0/10

Benchmark task

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

Beach

Same task instructions

Creativity, perspective and visual beauty.

The judgment

GPT-5.6 Sol

The purple-to-gold sunset, framing palms and varied beach activities create an appealing, coherent illustration. The sun’s reflection establishes a clear focal path. Figures and animals are recognizable but geometrically simplified; airborne dolphins lack convincing splashes, and the boat reflection is schematic. Clean silhouettes and playful details succeed more strongly than anatomical depth or material realism.

GPT-6.1 Terra Low

A coherent sunset scene demonstrates the beach, animals, birds and reflections. Flowing silhouettes, warm color transitions and intact attachments are its strongest properties. Simplified anatomy, the turtle's elevated viewing angle and symbolic surface effects constrain drawing complexity and physical depth.

Score breakdown

CategoryGPT-5.6 SolGPT-6.1 Terra Low
Task & likeness8.5/108.0/10
Anatomy & construction6.0/105.5/10
Space & placement7.0/105.5/10
Light & reflections6.5/106.5/10
Purposeful detail7.0/106.0/10
Artistry & character6.5/105.0/10
Materials & effects6.5/105.5/10
Visual integrity7.0/107.5/10

Benchmark task

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

Ground Truth

Same task instructions

Physical reasoning, light and visual reconstruction.

The judgment

GPT-5.6 Sol

This benchmark has not been assessed yet.

GPT-6.1 Terra Low

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

Same task instructions

Scene composition and interacting subjects.

The judgment

GPT-5.6 Sol

Expressive faces, bold silhouettes and layered waves make an appealing cartoon. The raccoon sits convincingly behind the dog's shoulders, and the dog's forward paw reaches the steering grip. Steering construction and seated support remain somewhat ambiguous. The glowing sunset lacks a corresponding warm reflection or consistent illumination on the riders.

GPT-6.1 Terra Low

Recognizable animals, a coherent craft and sweeping wake make an appealing cartoon. Basic limb construction, weakly demonstrated raccoon seating and limited shared perspective constrain the scene. Small identifying details work well, while lighting and materials remain broadly graphic.

Score breakdown

CategoryGPT-5.6 SolGPT-6.1 Terra Low
Task & likeness6.5/106.5/10
Anatomy & construction5.0/105.0/10
Space & placement6.5/105.5/10
Light & reflections6.5/104.5/10
Purposeful detail7.5/106.0/10
Artistry & character5.0/105.0/10
Materials & effects7.0/105.0/10
Visual integrity5.0/106.0/10

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

Same task instructions

Subject construction and spatial relationships.

The judgment

GPT-5.6 Sol

The expressive pelican and balanced coastal composition remain appealing, but a sky-colored slit between the neck contours above the wing leaves the central anatomy incoherent. This visible construction and layering defect prevents a clean-integrity assessment. Clustered feet lack clear pedal contacts and the chain routing is schematic; lighting and water reflections remain graphic.

GPT-6.1 Terra Low

A coherent coastal illustration with a distinctive pelican, controlled contours and clearly organised bicycle wheels. Visible saddle support and shaped neck and wing contours earn credit beyond basic geometric construction. Rubbery legs, unresolved pedal contacts and absent steering contact limit the riding action. Lighting and materials remain restrained and spatially shallow.

Score breakdown

CategoryGPT-5.6 SolGPT-6.1 Terra Low
Task & likeness8.5/107.0/10
Anatomy & construction5.0/105.5/10
Space & placement7.5/106.0/10
Light & reflections7.5/105.5/10
Purposeful detail8.0/106.5/10
Artistry & character6.5/106.0/10
Materials & effects7.0/106.0/10
Visual integrity4.5/106.0/10

Benchmark task

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