STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Terra Low vs GLM-5.3-Flash

GLM-5.3-Flash leads GPT-6.1 Terra Low by 7.2 points on StealthMark, 48.5 to 41.3. It leads on 6 of 9 benchmarks, including Foresight, and GPT-6.1 Terra Low on 2, including Latch, with 1 tied. Ox Alpha scores higher on Ground Truth.

See the difference ↘
All results ↗
Model guide ↗

Overall StealthMark

41.3/100Overall rank 35/55
48.5/100Overall rank 20/55

General Intelligence

34.3/100
42.3/100

Visual Intelligence

53.1/100
59.4/100

Open or local

Local modelOpen model · MIT

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6.1 Terra Low
  • GLM-5.3-Flash
  • Other models
  • Median

DATASHEET

Specs and pricing

  • GPT-6.1 Terra Low
  • GLM-5.3-Flash
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Terra Low: No list priceGLM-5.3-Flash: $0.50$0.15 input
Context windowTokens per request, max output below
GPT-6.1 Terra Low: Not publishedGLM-5.3-Flash: 1M131K max output
Output speedTokens per second, our measurement
GPT-6.1 Terra Low: Not measuredGLM-5.3-Flash: 89tokens/s
SizeTotal and active parameters
GPT-6.1 Terra Low: Not disclosedGLM-5.3-Flash: 320B18B active
Developer
Not publishedZ.AI
Released
Not published26 Aug 2026
Input → output
Not publishedText, image → text
Architecture
Not publishedHybrid sparse and linear attention MoE

Full datasheets, every price and sourceGLM-5.3-Flash ↗

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

GLM-5.3-Flash 47.0/100Rank 21/51

Survived 1 of 3
Foresight: complete playing field
Level 316 ptsTurn 20 / 20

Points per level

LevelGPT-6.1 Terra LowGLM-5.3-Flash
Level 1Second Thoughts
4 ptsOut of lives
9 ptsOut of lives
Level 2Pressure Pot
8 ptsOut of lives
6 ptsOut of lives
Level 3Hide or Flight
9 ptsSurvived
16 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-6.1 Terra Low 62.4/100Rank 23/52

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

GLM-5.3-Flash 4.0/100Rank 52/523 of 5 levels

3 of 5 played
Latch: complete playing field
Level 30.6 ptsTurn 33 / 36

Points per level

LevelGPT-6.1 Terra LowGLM-5.3-Flash
Level 1Hold the door
5.2 ptsCleared
4.4 ptsCleared
Level 2Crossfeed
9.2 ptsCleared
5.2 ptsFinished early
Level 3Relay vault
18.8 ptsCleared
0.6 ptsFinished early
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.

GLM-5.3-Flash

The setup is recognizable, but the paint interaction remains poorly established and off-center. The first wall and floor images provide coherent placement, scale, silhouette and occlusion cues, with faint lower echoes. Missing receding chains, nested imagery and ordered emitter mappings leave the reflection system heavily simplified. Dull shading does not convincingly depict polished steel or mirrors.

Score breakdown

CategoryGPT-6.1 Terra LowGLM-5.3-Flash
State at 600 ms22.0/2514.0/25
Camera and placement4.0/159.0/15
Reflections10.0/12021.5/120
Materials and scale6.0/103.5/10
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.

GLM-5.3-Flash

The expressive emerald face, ivory horns, gold accents and fine veining closely match the brief. Rounded volumes and layered shading create an appealing mascot. Rear hoof placement is cramped, lighting is somewhat inconsistent, and conspicuous white patches behind the muzzle interrupt the finish. Surfaces remain visibly stylized rather than photographic.

Score breakdown

CategoryGPT-6.1 Terra LowGLM-5.3-Flash
Task & likeness4.0/108.5/10
Anatomy & construction3.5/107.5/10
Space & placement4.5/107.5/10
Light & reflections5.5/108.0/10
Purposeful detail5.5/107.5/10
Artistry & character5.0/107.5/10
Materials & effects5.5/107.5/10
Visual integrity4.0/107.0/10

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.

GLM-5.3-Flash

A rounded jade bull raising a hoof tests anatomy, balance and the appearance of polished stone and metal.

Mona Lisa

Different 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.

GLM-5.3-Flash

The crossed arms, green dress and hazy landscape clearly evoke Mona Lisa. Replication is limited by the frontal pose, oversized eyes, elongated face and pronounced lips. Overlapping finger strips lack convincing knuckles and palm volume. The balanced framing and soft shading provide cohesion, but simplified anatomy, repetitive folds and blurred scenery keep the portrait basic.

Score breakdown

CategoryGPT-6.1 Terra LowGLM-5.3-Flash
Task & likeness5.0/104.5/10
Anatomy & construction4.5/104.5/10
Space & placement5.0/106.0/10
Light & reflections6.0/106.0/10
Purposeful detail5.0/105.0/10
Artistry & character5.5/105.0/10
Materials & effects5.0/105.5/10
Visual integrity6.0/104.0/10

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-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.

GLM-5.3-Flash

Framing palms, a vivid sunset palette and balanced kite and umbrella create an appealing beach illustration. Layered water and shoreline give the scene depth, while aligned reflections reinforce the sunset. Small accessories add character and reward inspection. Figures and animals remain schematic, some overlaps are difficult to read, and simplified shadows and flat surfaces limit physical richness.

Score breakdown

CategoryGPT-6.1 Terra LowGLM-5.3-Flash
Task & likeness8.0/108.0/10
Anatomy & construction5.5/107.0/10
Space & placement5.5/108.0/10
Light & reflections6.5/108.0/10
Purposeful detail6.0/108.0/10
Artistry & character5.0/108.5/10
Materials & effects5.5/106.5/10
Visual integrity7.5/108.0/10

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.

GLM-5.3-Flash

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-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.

GLM-5.3-Flash

Recognizable animals, a supported riding pose and an energetic diagonal composition make the scene readable. Character details and spray strengthen its appeal. Simple limb construction, limited directional lighting and an unresolved steering connection constrain the drawing's physical precision and complexity.

Score breakdown

CategoryGPT-6.1 Terra LowGLM-5.3-Flash
Task & likeness6.5/107.0/10
Anatomy & construction5.0/105.0/10
Space & placement5.5/106.0/10
Light & reflections4.5/105.0/10
Purposeful detail6.0/106.5/10
Artistry & character5.0/104.0/10
Materials & effects5.0/106.0/10
Visual integrity6.0/106.0/10

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

Different 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.

GLM-5.3-Flash

The pelican, bicycle and seaside setting form a clear, appealing illustration. Circular wheels, readable frame tubes and clean silhouettes support the action. The legs connect to the body, but the far foot's pedal contact and wing-to-handlebar junction are cramped. Simple shading, uniform wave marks and limited surface texture keep the rendering relatively flat.

Score breakdown

CategoryGPT-6.1 Terra LowGLM-5.3-Flash
Task & likeness7.0/108.5/10
Anatomy & construction5.5/107.5/10
Space & placement6.0/107.5/10
Light & reflections5.5/106.5/10
Purposeful detail6.5/107.0/10
Artistry & character6.0/108.0/10
Materials & effects6.0/106.5/10
Visual integrity6.0/108.0/10

Benchmark task

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