STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Terra Low vs Hy4 preview

Hy4 preview leads GPT-6.1 Terra Low by 2.6 points on StealthMark, 43.9 to 41.3. GPT-6.1 Terra Low leads on 5 of 9 benchmarks, including Latch, and Hy4 preview on 4, including Foresight. Hy4 preview scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

41.3/100Overall rank 35/55
43.9/100Overall rank 31/55

General Intelligence

34.3/100
41.3/100

Visual Intelligence

53.1/100
48.6/100

Open or local

Open modelApache-2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6.1 Terra Low
  • Hy4 preview
  • Other models
  • Median

DATASHEET

Specs and pricing

  • GPT-6.1 Terra Low
  • Hy4 preview
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Terra Low: No list priceHy4 preview: $2.50$0.83 input
Context windowTokens per request, max output below
GPT-6.1 Terra Low: Not publishedHy4 preview: 1M64K max output
Output speedTokens per second, our measurement
GPT-6.1 Terra Low: Not measuredHy4 preview: 64tokens/s
SizeTotal and active parameters
GPT-6.1 Terra Low: Not disclosedHy4 preview: 770B49B active
Developer
Not publishedTencent Hy Team
Released
Not published28 Aug 2026
Origin
Not publishedChina
Input → output
Not publishedText → text
Architecture
Not publishedMoE; 78-layer backbone with Gated DSA, 256 routed experts + 1 shared expert, top-8 routed experts active, plus native MTP layer

Full datasheets, every price and sourceHy4 preview ↗

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

Hy4 preview 53.1/100Rank 15/51

Survived 1 of 3
Foresight: complete playing field
Level 311 ptsTurn 16 / 20

Points per level

LevelGPT-6.1 Terra LowHy4 preview
Level 1Second Thoughts
4 ptsOut of lives
26 ptsSurvived
Level 2Pressure Pot
8 ptsOut of lives
6 ptsOut of lives
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

Hy4 preview 35.6/100Rank 35/52

Cleared 3 of 5
Latch: complete playing field
Level 518.2 ptsTurn 19 / 40

Points per level

LevelGPT-6.1 Terra LowHy4 preview
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.2 ptsCleared
6 ptsFinished early
Level 3Relay vault
18.8 ptsCleared
18 ptsCleared
Level 4Passing bay
10.2 ptsFinished early
15.8 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
20.6 ptsCleared
18.2 ptsFinished early

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.

Hy4 preview

The central sphere, compact airborne black bead and broad paint ordering are supported. Contact and transport history remain partly unresolved. The optical system provides only isolated first images and light patches, with little evidence of the extensive ordered reflection structure. Rounded metal and paint gloss are more successful than the reflected contents.

Score breakdown

CategoryGPT-6.1 Terra LowHy4 preview
State at 600 ms22.0/2518.0/25
Camera and placement4.0/1511.5/15
Reflections10.0/12029.5/120
Materials and scale6.0/107.5/10
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.

Hy4 preview

A cohesive, appealing illustration with a serene face, luminous palette and complete framing. The separated head and torso weaken anatomical coherence, while crowded wing attachments and angular sash folds limit the requested suppleness. Clean execution and decorative detail exceed the clarity of the underlying construction.

Score breakdown

CategoryGPT-6.1 Terra LowHy4 preview
Task & likeness4.0/106.0/10
Anatomy & construction3.5/105.5/10
Space & placement4.5/107.5/10
Light & reflections5.5/107.0/10
Purposeful detail5.5/106.5/10
Artistry & character5.0/105.0/10
Materials & effects5.5/107.0/10
Visual integrity4.0/105.5/10

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.

Hy4 preview

A young blue dragon floating among clouds tests curved anatomy, expressive features and the contrast between soft clouds and glossy surfaces.

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.

Hy4 preview

A recognizable but basic Mona Lisa interpretation with a cohesive earthy palette and atmospheric hills. The rigid neck, generic face and unresolved folded-hand pose limit replication and anatomy. Large silhouettes and layer boundaries are comparatively clear, warranting stronger integrity credit than the sparse detail and simplified construction.

Score breakdown

CategoryGPT-6.1 Terra LowHy4 preview
Task & likeness5.0/102.5/10
Anatomy & construction4.5/102.5/10
Space & placement5.0/102.5/10
Light & reflections6.0/101.5/10
Purposeful detail5.0/102.5/10
Artistry & character5.5/101.5/10
Materials & effects5.0/102.5/10
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

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.

Hy4 preview

A cheerful beach illustration fulfills the visible subject requirements with coherent foreground construction and a harmonious sunset palette. Shallow depth, schematic reflections, ambiguous blue airborne forms and exposed geometry beneath the sunset limit its finish. Small accessories are readable, but materials and surface detail remain simplified.

Score breakdown

CategoryGPT-6.1 Terra LowHy4 preview
Task & likeness8.0/108.5/10
Anatomy & construction5.5/105.5/10
Space & placement5.5/106.5/10
Light & reflections6.5/105.0/10
Purposeful detail6.0/106.0/10
Artistry & character5.0/105.5/10
Materials & effects5.5/105.0/10
Visual integrity7.5/106.0/10

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.

Hy4 preview

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.

Hy4 preview

A lively cartoon communicates the animal pair traveling across water. Curving waves, rising spray and locally modeled gray forms strengthen motion and volume. Ambiguous seating, simplified joints and unclear control routing limit construction. Competing focal elements, decorative foam and inconsistent illumination leave the finish uneven.

Score breakdown

CategoryGPT-6.1 Terra LowHy4 preview
Task & likeness6.5/107.0/10
Anatomy & construction5.0/104.0/10
Space & placement5.5/106.0/10
Light & reflections4.5/106.5/10
Purposeful detail6.0/105.5/10
Artistry & character5.0/104.5/10
Materials & effects5.0/105.5/10
Visual integrity6.0/105.0/10

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-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.

Hy4 preview

A recognizable, playful pelican cyclist with readable wheels, accessories and landscape layers. Form shading and ground shadows provide competent depth. Angular legs, uncertain pedal engagement and absent steering contact limit the riding construction; crowded overlaps and simple surfaces constrain refinement.

Score breakdown

CategoryGPT-6.1 Terra LowHy4 preview
Task & likeness7.0/107.5/10
Anatomy & construction5.5/104.5/10
Space & placement6.0/106.5/10
Light & reflections5.5/107.0/10
Purposeful detail6.5/106.0/10
Artistry & character6.0/105.0/10
Materials & effects6.0/105.0/10
Visual integrity6.0/107.0/10

Benchmark task

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