GPT-5.5 38.7/100Rank 37/512 of 3 levels

STEALTHMARK · HEAD TO HEAD
All comparisons ↗GPT-6.1 Terra Low leads GPT-5.5 by 4.8 points on StealthMark, 41.3 to 36.5. It leads on 7 of 9 benchmarks, including Foresight, and GPT-5.5 on 2, including Latch. GPT-6.1 Terra Low scores higher on Mona Lisa, with its largest category advantage in anatomy & construction.
See the difference ↘BENCHMARK BY BENCHMARK
DATASHEET
Full datasheets, every price and sourceGPT-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 ↗


GPT-5.5
The paint ordering and separate black bead support part of the physical state, but adhesion and rotational transport remain only partly established. The sweeping cyan arc and long crimson lobes do not clearly communicate the limited time since their respective impacts. The main sphere is too large and too low, and the black bead is below its required projected position. Displaced isolated sphere images, a flattened floor echo and missing recursive, nested and emitter reflections provide little coherent optical structure. The colored paint is excessively bulky for the specified quantities.
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.
| Category | GPT-5.5 | GPT-6.1 Terra Low |
|---|---|---|
| State at 600 ms | 15.0/25 | 22.0/25 |
| Camera and placement | 6.0/15 | 4.0/15 |
| Reflections | 5.0/120 | 10.0/120 |
| Materials and scale | 6.0/10 | 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.


GPT-5.5
Six pale, scaled lobes form a balanced radial arrangement, but they remain separate capsules rather than an interlocking serpent knot. There are no crossings, alternating overlaps, or crisp inner bends; the central hexagon is an isolated outline. Small outward-facing heads sit within the lobes without integrated necks. Soft shading and tidy contours provide some finish, while repetitive oval scales and cartoon faces limit organic credibility.
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.
| Category | GPT-5.5 | GPT-6.1 Terra Low |
|---|---|---|
| Task & likeness | 3.0/10 | 4.0/10 |
| Anatomy & construction | 3.0/10 | 3.5/10 |
| Space & placement | 5.0/10 | 4.5/10 |
| Light & reflections | 5.0/10 | 5.5/10 |
| Purposeful detail | 4.5/10 | 5.5/10 |
| Artistry & character | 4.0/10 | 5.0/10 |
| Materials & effects | 4.5/10 | 5.5/10 |
| Visual integrity | 7.0/10 | 4.0/10 |
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.
Precise visual recall and portrait reconstruction.


GPT-5.5
The veil, restrained smile, crossed hands and muted landscape establish Mona Lisa references. The oversized frontal face and schematic features weaken likeness and expression, while fingerless tapered hand shapes leave anatomy unresolved. Clean contours and balanced framing provide coherence, but sparse garment detail, broad landscape bands and shallow shading limit the portrait's sophistication.
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.
| Category | GPT-5.5 | GPT-6.1 Terra Low |
|---|---|---|
| Task & likeness | 1.5/10 | 5.0/10 |
| Anatomy & construction | 1.5/10 | 4.5/10 |
| Space & placement | 1.5/10 | 5.0/10 |
| Light & reflections | 2.0/10 | 6.0/10 |
| Purposeful detail | 2.5/10 | 5.0/10 |
| Artistry & character | 1.5/10 | 5.5/10 |
| Materials & effects | 2.0/10 | 5.0/10 |
| Visual integrity | 1.5/10 | 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.


GPT-5.5
The sunset, palms, birds, playful animals and ball clearly establish the requested beach scene. Warm sky gradients and clean silhouettes make it appealing. Animal construction is underdeveloped: torso and limb connections are unclear, especially in the round-eared foreground figure. The dolphin lacks a convincing splash, and broad reflection bands suggest sunset light without resolving its behavior on water.
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.
| Category | GPT-5.5 | GPT-6.1 Terra Low |
|---|---|---|
| Task & likeness | 7.0/10 | 8.0/10 |
| Anatomy & construction | 2.5/10 | 5.5/10 |
| Space & placement | 3.0/10 | 5.5/10 |
| Light & reflections | 3.0/10 | 6.5/10 |
| Purposeful detail | 3.0/10 | 6.0/10 |
| Artistry & character | 3.0/10 | 5.0/10 |
| Materials & effects | 3.0/10 | 5.5/10 |
| Visual integrity | 3.5/10 | 7.5/10 |
A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.
Physical reasoning, light and visual reconstruction.


GPT-5.5
This benchmark has not been assessed yet.
GPT-6.1 Terra Low
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.


GPT-5.5
The raccoon's masked face, bright hull and sweeping wake make the scene readable and lively. The dog is much less resolved: its head is ambiguous, overlapping brown forms obscure its anatomy, and its paws do not visibly grip the controls. Smooth shapes and cheerful colors provide appeal, but weak steering construction and limited depth keep the drawing uneven.
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.
| Category | GPT-5.5 | GPT-6.1 Terra Low |
|---|---|---|
| Task & likeness | 3.5/10 | 6.5/10 |
| Anatomy & construction | 3.0/10 | 5.0/10 |
| Space & placement | 4.5/10 | 5.5/10 |
| Light & reflections | 5.0/10 | 4.5/10 |
| Purposeful detail | 3.5/10 | 6.0/10 |
| Artistry & character | 3.0/10 | 5.0/10 |
| Materials & effects | 5.0/10 | 5.0/10 |
| Visual integrity | 3.0/10 | 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.


GPT-5.5
The oversized bill, bright bicycle and sunset create an appealing, recognizable cartoon. Riding mechanics are less convincing: the wing has no clear steering contact, leg attachments are uneven, and feet do not visibly engage pedals. A dark notch complicates the rear neck junction. Clean contours and orderly spokes provide polish, while simplified anatomy and lighting limit depth.
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.
| Category | GPT-5.5 | GPT-6.1 Terra Low |
|---|---|---|
| Task & likeness | 7.5/10 | 7.0/10 |
| Anatomy & construction | 4.5/10 | 5.5/10 |
| Space & placement | 6.5/10 | 6.0/10 |
| Light & reflections | 6.5/10 | 5.5/10 |
| Purposeful detail | 5.5/10 | 6.5/10 |
| Artistry & character | 5.0/10 | 6.0/10 |
| Materials & effects | 6.0/10 | 6.0/10 |
| Visual integrity | 7.5/10 | 6.0/10 |
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.