GPT-6.1 Terra 62.0/100Rank 9/50

STEALTHMARK · HEAD TO HEAD
All comparisons ↗GPT-6.1 Terra leads Muse Spark Open by 16.3 points on StealthMark, 60.4 to 44.1. It leads on all 9 benchmarks. GPT-6.1 Terra scores higher on Newton's Mirror, with its largest category advantage in reflections.
See the difference ↘On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.
BENCHMARK BY BENCHMARK
DATASHEET
GPT-6.1 Terra scores higher on StealthMark. Muse Spark Open is 18% cheaper per output token. Both take about 1.05M tokens of context.
Full datasheets, every price and sourceGPT-6.1 Terra ↗Muse Spark Open ↗
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-6.1 Terra
The sphere, airborne black and first reflected silhouettes preserve important geometry within the portrait frame. Paint deformation, contact order and forward transport are supported, with a small crimson endpoint overshoot. Major optical omissions dominate: short finite reflection sequences and smooth bands replace extensive, spatially ordered mirror imagery. Dark gloss and crisp upper emitter shapes provide partial material credit.
Muse Spark Open
The airborne black blob and deformed paint support the broad contact sequence, although cyan attachment and wheel-directed transport remain partial. The sphere and black blob have substantial framing errors. The dominant limitation is the largely absent mirror system: faint wall circles and isolated highlights provide little evidence of recursive room geometry or curved nested reflections. Oversized compact paint features and diffuse material treatment further limit credit.
| Category | GPT-6.1 Terra | Muse Spark Open |
|---|---|---|
| State at 600 ms | 23.0/25 | 14.0/25 |
| Camera and placement | 11.0/15 | 6.0/15 |
| Reflections | 33.0/120 | 8.0/120 |
| Materials and scale | 7.5/10 | 3.5/10 |
| 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-6.1 Terra
A balanced serpent emblem with six attached outward heads, delicate scales and softly rounded bodies. Its compact silhouette reads clearly, but central routing does not establish every alternating crossing or crisp inward corner. Repetitive texture, limited facial anatomy and weak contact shadows constrain its organic character.
Muse Spark Open
The rounded silhouette and asymmetric expression make an appealing baby elephant, supported by a quiet background and grounding shadow. The protective action remains difficult to read: forefeet cannot be confidently traced into a grip, and seed contact is crowded by fine lines. Controlled simple shapes provide charm, but limited anatomical clarity, shading and surface detail leave the execution uneven.
| Category | GPT-6.1 Terra | Muse Spark Open |
|---|---|---|
| Task & likeness | 7.5/10 | 5.0/10 |
| Anatomy & construction | 6.5/10 | 4.5/10 |
| Space & placement | 6.5/10 | 6.0/10 |
| Light & reflections | 6.0/10 | 5.0/10 |
| Purposeful detail | 6.5/10 | 6.0/10 |
| Artistry & character | 6.5/10 | 5.0/10 |
| Materials & effects | 6.0/10 | 5.0/10 |
| Visual integrity | 6.0/10 | 6.5/10 |
GPT-6.1 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.
Muse Spark Open
A small elephant protecting a delicate seed tests expressive anatomy, physical contact and contrasting organic materials.
Precise visual recall and portrait reconstruction.


GPT-6.1 Terra
A recognizable interpretation with developed facial shading, shaped sleeve folds and purposeful small features. These strengths support modest upward calibration, while the frontal torso, elongated proportions, schematic finger joints and unresolved seated support keep replication and construction uneven.
Muse Spark Open
A recognizable, orderly interpretation with clean major contours, connected body forms and modest facial shading. Wide eyes, frontal symmetry and schematic hands limit likeness and expression. Layered scenery establishes basic depth, but shallow arm overlaps, flat clothing and sparse fine detail keep the execution basic and uneven.
| Category | GPT-6.1 Terra | Muse Spark Open |
|---|---|---|
| Task & likeness | 5.5/10 | 3.0/10 |
| Anatomy & construction | 6.5/10 | 3.0/10 |
| Space & placement | 4.5/10 | 5.0/10 |
| Light & reflections | 6.5/10 | 4.5/10 |
| Purposeful detail | 6.0/10 | 4.0/10 |
| Artistry & character | 6.0/10 | 3.0/10 |
| Materials & effects | 6.0/10 | 4.0/10 |
| Visual integrity | 6.5/10 | 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-6.1 Terra
A coherent sunset illustration with clear prompt fulfillment, controlled framing and varied, purposeful small details. Simplified joints, frontal staging, flattened animal forms and weakly directional shadows limit its anatomical, spatial and physical sophistication.
Muse Spark Open
A coherent sunset beach with readable activities, balanced framing and controlled colour transitions. Small accessories add interest, but schematic anatomy, limited surface detail, weak directional shadows and a geometric reflection constrain its finish. Most shapes and overlaps remain clean.
| Category | GPT-6.1 Terra | Muse Spark Open |
|---|---|---|
| Task & likeness | 8.5/10 | 8.0/10 |
| Anatomy & construction | 7.5/10 | 6.0/10 |
| Space & placement | 6.5/10 | 6.5/10 |
| Light & reflections | 5.5/10 | 5.5/10 |
| Purposeful detail | 7.5/10 | 6.5/10 |
| Artistry & character | 7.0/10 | 5.5/10 |
| Materials & effects | 6.5/10 | 6.0/10 |
| Visual integrity | 7.5/10 | 8.0/10 |
A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.
Physical reasoning, light and visual reconstruction.


GPT-6.1 Terra
This benchmark has not been assessed yet.
Muse Spark Open
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-6.1 Terra
A coherent cartoon with expressive animals, readable steering and a clear wake. Fine facial and hull details reward inspection. The main limits are the boatlike craft, simplified joints, weakly braced frontal raccoon and minimal directional lighting or material depth.
Muse Spark Open
Expressive faces, distinct accessories and clean color separation make the scene appealing and recognizable. Character detail is stronger than the functional construction: steering contact, limb overlaps and seating remain ambiguous. The readable hull and lively spray establish motion, while limited directional shading and simplified surfaces constrain depth and physical coherence.
| Category | GPT-6.1 Terra | Muse Spark Open |
|---|---|---|
| Task & likeness | 6.5/10 | 4.0/10 |
| Anatomy & construction | 5.5/10 | 3.0/10 |
| Space & placement | 6.0/10 | 6.0/10 |
| Light & reflections | 5.0/10 | 4.5/10 |
| Purposeful detail | 7.0/10 | 7.0/10 |
| Artistry & character | 6.0/10 | 3.5/10 |
| Materials & effects | 6.0/10 | 5.0/10 |
| Visual integrity | 7.0/10 | 5.0/10 |
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-6.1 Terra
A coherent pelican cyclist with expressive proportions, purposeful feather detail and developed bicycle machinery. Continuous body contours, aligned wheels and readable pedal contacts support the scene. Simplified articulation, shallow modelling and an unresolved steering connection limit construction and placement.
Muse Spark Open
A controlled, appealing cartoon with a recognizable pelican, expressive face and clean curved forms. Feather lines, spokes and bill shading provide useful complexity. Aligned wheels and a ground shadow establish placement, but uncertain pedal contacts and obscured mechanical connections weaken support and riding action. Lighting remains loosely coordinated with the sun.
| Category | GPT-6.1 Terra | Muse Spark Open |
|---|---|---|
| Task & likeness | 7.0/10 | 7.5/10 |
| Anatomy & construction | 7.0/10 | 5.0/10 |
| Space & placement | 6.0/10 | 6.0/10 |
| Light & reflections | 5.5/10 | 5.0/10 |
| Purposeful detail | 7.0/10 | 6.5/10 |
| Artistry & character | 6.5/10 | 5.5/10 |
| Materials & effects | 5.5/10 | 6.0/10 |
| Visual integrity | 6.0/10 | 7.5/10 |
A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.