STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Claude Haiku 5.5 vs GPT-6.1 Terra Low

Claude Haiku 5.5 leads GPT-6.1 Terra Low by 8.2 points on StealthMark, 49.5 to 41.3. It leads on 6 of 9 benchmarks, including Latch, and GPT-6.1 Terra Low on 3, including Foresight. Claude Haiku 5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

49.5/100Overall rank 18/55
41.3/100Overall rank 35/55

General Intelligence

47.6/100
34.3/100

Visual Intelligence

52.8/100
53.1/100

BENCHMARK BY BENCHMARK

Where each model leads

  • Claude Haiku 5.5
  • GPT-6.1 Terra Low
  • Other models
  • Median

DATASHEET

Specs and pricing

  • Claude Haiku 5.5
  • GPT-6.1 Terra Low
  • Other models
  • Median
PricePer 1M output tokens, input below
Claude Haiku 5.5: $0.50$0.10 inputGPT-6.1 Terra Low: No list price
Context windowTokens per request, max output below
Claude Haiku 5.5: 1M128K max outputGPT-6.1 Terra Low: Not published
Output speedTokens per second, our measurement
Claude Haiku 5.5: 402tokens/sGPT-6.1 Terra Low: Not measured
Developer
AnthropicNot published
Released
7 Oct 2026Not published
Origin
United StatesNot published
Input → output
Text, image → textNot published

Full datasheets, every price and sourceClaude Haiku 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.

Claude Haiku 5.5 34.4/100Rank 28/51

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

GPT-6.1 Terra Low 36.1/100Rank 26/51

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

Points per level

LevelClaude Haiku 5.5GPT-6.1 Terra Low
Level 1Second Thoughts
4 ptsOut of lives
4 ptsOut of lives
Level 2Pressure Pot
7 ptsOut of lives
8 ptsOut of lives
Level 3Hide or Flight
9 ptsSurvived
9 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.

Claude Haiku 5.5 78.3/100Rank 11/52

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

GPT-6.1 Terra Low 62.4/100Rank 23/52

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

Points per level

LevelClaude Haiku 5.5GPT-6.1 Terra Low
Level 1Hold the door
5 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.2 ptsCleared
Level 3Relay vault
18.8 ptsCleared
18.8 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
10.2 ptsFinished early
Level 5Second thoughts
20.6 ptsCleared
20.6 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

Claude Haiku 5.5

The centered sphere, compact airborne black blob and differentiated cyan/crimson interaction support substantial state and placement credit. The few recognizable sphere and panel images establish limited optical relationships, but most of the required mirror system is missing. Rounded volume and localized paint warrant substantial material credit despite the soft, illustrative finish.

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra Low
State at 600 ms25.0/2522.0/25
Camera and placement8.0/154.0/15
Reflections24.5/12010.0/120
Materials and scale7.5/106.0/10
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

Claude Haiku 5.5

A coherent coral squid emblem with a compact mantle, restrained face and clean centered presentation. Its radial silhouette and floating placement work, but sharp arm tips, crowded roots and sparse surface modeling limit softness, construction and finish.

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra Low
Task & likeness6.5/104.0/10
Anatomy & construction4.0/103.5/10
Space & placement6.5/104.5/10
Light & reflections4.0/105.5/10
Purposeful detail3.5/105.5/10
Artistry & character3.5/105.0/10
Materials & effects4.5/105.5/10
Visual integrity7.0/104.0/10

Benchmark task

Claude Haiku 5.5

A coral squid with spreading arms tests connected anatomy, balanced composition and soft surface shading.

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.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

Claude Haiku 5.5

A recognizable but basic Mona Lisa reinterpretation. Clean contours and smooth facial lighting provide coherence and volume. Replication remains limited by the frontal pose, elongated neck, schematic expression, unresolved crossed hands and sparse landscape. Lighting is more successful than anatomical construction and purposeful detail.

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra Low
Task & likeness3.0/105.0/10
Anatomy & construction4.0/104.5/10
Space & placement4.0/105.0/10
Light & reflections5.5/106.0/10
Purposeful detail2.5/105.0/10
Artistry & character3.5/105.5/10
Materials & effects2.5/105.0/10
Visual integrity5.5/106.0/10

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

Claude Haiku 5.5

A cheerful, coherent beach illustration with attractive sunset colors, readable accessories and clean silhouettes. Its sun and sailboat reflections establish useful physical relationships. Simple animal construction, flattened foreground placement, sparse directional shadows and minimally differentiated surfaces limit its drawing refinement.

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra Low
Task & likeness8.5/108.0/10
Anatomy & construction6.5/105.5/10
Space & placement7.0/105.5/10
Light & reflections7.0/106.5/10
Purposeful detail7.0/106.0/10
Artistry & character6.0/105.0/10
Materials & effects6.0/105.5/10
Visual integrity8.5/107.5/10

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

Claude Haiku 5.5

This benchmark has not been assessed yet.

GPT-6.1 Terra Low

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

Claude Haiku 5.5

A tidy, appealing cartoon with recognizable animals and a pleasing sunset palette. Steering lacks visible controls, while schematic limbs and uncertain raccoon support weaken the requested interaction. Shallow vehicle construction, flat character lighting and modest displacement limit physical coherence. Clean shapes and readable identifying details remain strengths.

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra Low
Task & likeness4.0/106.5/10
Anatomy & construction3.5/105.0/10
Space & placement5.5/105.5/10
Light & reflections4.0/104.5/10
Purposeful detail5.5/106.0/10
Artistry & character4.5/105.0/10
Materials & effects5.5/105.0/10
Visual integrity4.5/106.0/10

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

Same task instructions

Subject construction and spatial relationships.

The judgment

Claude Haiku 5.5

A cheerful, recognizable illustration with clean contours and a balanced warm palette. Aligned wheels and readable frame geometry establish the bicycle, but shoulder construction, feet and steering contact remain imprecise. Sparse drivetrain detail, flat materials and absent grounding shadows limit anatomical and spatial conviction.

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra Low
Task & likeness8.0/107.0/10
Anatomy & construction5.5/105.5/10
Space & placement6.5/106.0/10
Light & reflections5.0/105.5/10
Purposeful detail6.0/106.5/10
Artistry & character5.0/106.0/10
Materials & effects5.0/106.0/10
Visual integrity8.0/106.0/10

Benchmark task

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