STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Terra Low vs Muse Spark 1.3

GPT-6.1 Terra Low leads Muse Spark 1.3 by 1.5 points on StealthMark, 41.3 to 39.8. Muse Spark 1.3 leads on 5 of 9 benchmarks, including Foresight, and GPT-6.1 Terra Low on 4, including Latch. GPT-6.1 Terra Low scores higher on Mona Lisa, with its largest category advantage in prompt & likeness.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

41.3/100Overall rank 35/55
39.8/100Overall rank 36/55

General Intelligence

34.3/100
38.3/100

Visual Intelligence

53.1/100
42.3/100

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6.1 Terra Low
  • Muse Spark 1.3
  • Other models
  • Median

DATASHEET

Specs and pricing

  • GPT-6.1 Terra Low
  • Muse Spark 1.3
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Terra Low: No list priceMuse Spark 1.3: $4.25$1.25 input
Context windowTokens per request, max output below
GPT-6.1 Terra Low: Not publishedMuse Spark 1.3: 1M
Output speedTokens per second, our measurement
GPT-6.1 Terra Low: Not measuredMuse Spark 1.3: 321tokens/s
Developer
Not publishedMeta
Released
Not published2 Sep 2026
Origin
Not publishedUnited States
Input → output
Not publishedText, image, video, audio, PDF → text

Full datasheets, every price and sourceMuse Spark 1.3 ↗

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-6.1 Terra Low 36.1/100Rank 26/51

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

Muse Spark 1.3 64.3/100Rank 6/51

Survived 2 of 3
Foresight: complete playing field
Level 311 ptsTurn 17 / 20

Points per level

LevelGPT-6.1 Terra LowMuse Spark 1.3
Level 1Second Thoughts
4 ptsOut of lives
26 ptsSurvived
Level 2Pressure Pot
8 ptsOut of lives
10 ptsSurvived
Level 3Hide or Flight
9 ptsSurvived
11 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-6.1 Terra Low 62.4/100Rank 23/52

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

Muse Spark 1.3 72.4/100Rank 29/523 of 5 levels

3 of 5 played
Latch: complete playing field
Level 318.8 ptsTurn 32 / 36

Points per level

LevelGPT-6.1 Terra LowMuse Spark 1.3
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.2 ptsCleared
9.8 ptsCleared
Level 3Relay vault
18.8 ptsCleared
18.8 ptsCleared
Level 4Passing bay
10.2 ptsFinished early
Pending
Level 5Second thoughts
20.6 ptsCleared
Not played

Newton's Mirror

Same task instructions

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

The judgment

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.

Muse Spark 1.3

The paint state is incorrectly and poorly drawn, despite a recognizable sphere-and-paint setup. The oversized sphere, oversized compact paint bodies, and blurred wall and floor images further limit the result. Isolated reflection cues provide very little support for the required repeated virtual rooms, nested spherical imagery or emitter mapping.

Score breakdown

CategoryGPT-6.1 Terra LowMuse Spark 1.3
State at 600 ms22.0/256.0/25
Camera and placement4.0/158.5/15
Reflections10.0/1205.5/120
Materials and scale6.0/104.0/10
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-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.

Muse Spark 1.3

The luminous creature and geometric mirror counterpart communicate self-recognition through a coherent palette and expressive eyes. The transformed reflection is purposeful. Simple oval anatomy, ambiguous reaching-arm construction, shallow spatial staging and limited illumination of nearby surfaces keep the illustration below exceptional execution.

Score breakdown

CategoryGPT-6.1 Terra LowMuse Spark 1.3
Task & likeness4.0/108.0/10
Anatomy & construction3.5/105.0/10
Space & placement4.5/106.5/10
Light & reflections5.5/107.0/10
Purposeful detail5.5/106.5/10
Artistry & character5.0/105.5/10
Materials & effects5.5/106.5/10
Visual integrity4.0/107.5/10

Benchmark task

GPT-6.1 Terra Low

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 1.3

An imagined creature encounters its reflection. The scene tests original character design, visual self-interpretation and the relationship between a subject and its reflected image.

Mona Lisa

Same task instructions

Precise visual recall and portrait reconstruction.

The judgment

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.

Muse Spark 1.3

Dark hair, a restrained smile and overlapping hands suggest Mona Lisa, but replication is weak. The face is markedly elongated, the hands are oval pads with faint finger strokes, and the atmospheric landscape is absent. Soft gradients provide basic volume, while the frontal symmetry, shallow space and sparse clothing detail limit the portrait’s drawing quality.

Score breakdown

CategoryGPT-6.1 Terra LowMuse Spark 1.3
Task & likeness5.0/101.0/10
Anatomy & construction4.5/101.5/10
Space & placement5.0/101.5/10
Light & reflections6.0/101.5/10
Purposeful detail5.0/101.0/10
Artistry & character5.5/101.5/10
Materials & effects5.0/101.5/10
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

Same task instructions

Creativity, perspective and visual beauty.

The judgment

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.

Muse Spark 1.3

The warm sunset, framing palms and colorful beach accessories create an appealing scene with the requested animals, birds and reflections. Construction remains schematic: the raised hand misses the kite string, and a doglike silhouette hangs above the water without clear support. The sun reflection establishes a focal path, but shadows and materials lack depth. An unexplained horizontal bar crosses the sun.

Score breakdown

CategoryGPT-6.1 Terra LowMuse Spark 1.3
Task & likeness8.0/106.5/10
Anatomy & construction5.5/103.0/10
Space & placement5.5/105.5/10
Light & reflections6.5/106.5/10
Purposeful detail6.0/105.0/10
Artistry & character5.0/103.5/10
Materials & effects5.5/103.0/10
Visual integrity7.5/103.5/10

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-6.1 Terra Low

This benchmark has not been assessed yet.

Muse Spark 1.3

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-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.

Muse Spark 1.3

The raccoon clearly rides on the dog's back, and the dog's paws reach the jet ski controls. Expressive faces and bright colors make the scene appealing. Simplified joints, crowded steering geometry and shallow hull perspective limit construction. The sun has no corresponding water reflection, and the splash shapes convey speed more clearly than convincing displacement.

Score breakdown

CategoryGPT-6.1 Terra LowMuse Spark 1.3
Task & likeness6.5/108.5/10
Anatomy & construction5.0/106.5/10
Space & placement5.5/107.0/10
Light & reflections4.5/105.0/10
Purposeful detail6.0/106.5/10
Artistry & character5.0/105.5/10
Materials & effects5.0/106.0/10
Visual integrity6.0/107.5/10

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

Same task instructions

Subject construction and spatial relationships.

The judgment

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.

Muse Spark 1.3

The pelican and bicycle are immediately recognizable, with an expressive face, bold bill and cheerful composition. Both legs connect to the body and reach pedal-like supports, but articulation, saddle support and wing contact with the handlebar remain unclear. Wheel alignment and layering are coherent. Simple landscape shapes, generic shadows and limited material variation constrain the finish.

Score breakdown

CategoryGPT-6.1 Terra LowMuse Spark 1.3
Task & likeness7.0/108.5/10
Anatomy & construction5.5/106.0/10
Space & placement6.0/107.0/10
Light & reflections5.5/106.0/10
Purposeful detail6.5/107.0/10
Artistry & character6.0/105.5/10
Materials & effects6.0/106.5/10
Visual integrity6.0/107.0/10

Benchmark task

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