STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Claude Haiku 5.5 vs GPT-6.1 Terra

GPT-6.1 Terra leads Claude Haiku 5.5 by 10.9 points on StealthMark, 60.4 to 49.5. It leads on 8 of 9 benchmarks, including Foresight, and Claude Haiku 5.5 on 1, including Latch. GPT-6.1 Terra scores higher on Raccoon, with its largest category advantage in anatomy & construction.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

49.5/100Overall rank 18/54
60.4/100Overall rank 9/54

General Intelligence

47.6/100
58.0/100

Visual Intelligence

52.8/100
64.9/100

Reasoning efficiency

On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.

Single-step reasoning Result quality weighed against reasoning tokens on a single problem

Multi-step reasoning Result quality weighed against reasoning tokens across connected steps, as in agentic workflows

  • Claude Haiku 5.5

BENCHMARK BY BENCHMARK

Where each model leads

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

DATASHEET

Specs and pricing

Claude Haiku 5.5 is 10× cheaper per output token. GPT-6.1 Terra scores higher on StealthMark. Both take about 1M tokens of context.

  • Claude Haiku 5.5
  • GPT-6.1 Terra
  • Other models
  • Median
PricePer 1M output tokens, input below
Claude Haiku 5.5: $0.5010× cheaper$0.10 inputGPT-6.1 Terra: $5$1 input
Context windowTokens per request, max output below
Claude Haiku 5.5: 1MTied128K max outputGPT-6.1 Terra: 1.05MTied128K max output
Output speedTokens per second, our measurement
Claude Haiku 5.5: 402tokens/sGPT-6.1 Terra: Not measured
Developer
AnthropicOpenAI
Released
7 Oct 202626 Oct 2026
Origin
United StatesBoth
Input → output
Text, image → textBoth

Full datasheets, every price and sourceClaude Haiku 5.5 ↗GPT-6.1 Terra ↗

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 27/50

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

GPT-6.1 Terra 62.0/100Rank 9/50

Survived 2 of 3
Foresight: complete playing field
Level 315 ptsTurn 20 / 20

Points per level

LevelClaude Haiku 5.5GPT-6.1 Terra
Level 1Second Thoughts
4 ptsOut of lives
21 ptsSurvived
Level 2Pressure Pot
7 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
9 ptsSurvived
15 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 11/51

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

GPT-6.1 Terra 77.7/100Rank 12/51

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

Points per level

LevelClaude Haiku 5.5GPT-6.1 Terra
Level 1Hold the door
5 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.8 ptsCleared
Level 3Relay vault
18.8 ptsCleared
19.2 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
17.8 ptsClearedFinished early · 3 beacons left
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

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra
State at 600 ms25.0/2523.0/25
Camera and placement8.0/1511.0/15
Reflections24.5/12033.0/120
Materials and scale7.5/107.5/10
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

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

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra
Task & likeness6.5/107.5/10
Anatomy & construction4.0/106.5/10
Space & placement6.5/106.5/10
Light & reflections4.0/106.0/10
Purposeful detail3.5/106.5/10
Artistry & character3.5/106.5/10
Materials & effects4.5/106.0/10
Visual integrity7.0/106.0/10

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

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

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra
Task & likeness3.0/105.5/10
Anatomy & construction4.0/106.5/10
Space & placement4.0/104.5/10
Light & reflections5.5/106.5/10
Purposeful detail2.5/106.0/10
Artistry & character3.5/106.0/10
Materials & effects2.5/106.0/10
Visual integrity5.5/106.5/10

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

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra
Task & likeness8.5/108.5/10
Anatomy & construction6.5/107.5/10
Space & placement7.0/106.5/10
Light & reflections7.0/105.5/10
Purposeful detail7.0/107.5/10
Artistry & character6.0/107.0/10
Materials & effects6.0/106.5/10
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

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

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.

Score breakdown

CategoryClaude Haiku 5.5GPT-6.1 Terra
Task & likeness4.0/106.5/10
Anatomy & construction3.5/105.5/10
Space & placement5.5/106.0/10
Light & reflections4.0/105.0/10
Purposeful detail5.5/107.0/10
Artistry & character4.5/106.0/10
Materials & effects5.5/106.0/10
Visual integrity4.5/107.0/10

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

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.

Score breakdown

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

Benchmark task

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