STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Claude Fable 5.2 vs GPT-6.1 Sol

Claude Fable 5.2 leads GPT-6.1 Sol by 12.0 points on StealthMark, 79.8 to 67.8. It leads on 7 of 9 benchmarks, including both games, and GPT-6.1 Sol on 2. Claude Fable 5.2 scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

79.8/100Overall rank 1/57
67.8/100Overall rank 5/57

General Intelligence

81.7/100
64.4/100

Visual Intelligence

76.0/100
74.1/100

Reasoning efficiency

How many reasoning tokens a model needs for the quality it delivers.

Single-step reasoning How much it reasons to understand a task

Multi-step reasoning How much it keeps reasoning as a task goes on

  • GPT-6.1 Sol

Cost efficiency

How much Performance you get for your money.

  • Claude Fable 5.2Not measured

BENCHMARK BY BENCHMARK

Where each model leads

  • Claude Fable 5.2
  • GPT-6.1 Sol
  • Other models
  • Median

DATASHEET

Specs and pricing

  • Claude Fable 5.2
  • GPT-6.1 Sol
  • Other models
  • Median
PricePer 1M output tokens, input below
Claude Fable 5.2: No list priceGPT-6.1 Sol: $10$2 input
Context windowTokens per request, max output below
Claude Fable 5.2: Not publishedGPT-6.1 Sol: 1.05M128K max output
Output speedTokens per second, our measurement
Claude Fable 5.2: Not measuredGPT-6.1 Sol: 51tokens/s
Developer
Not publishedOpenAI
Released
Not published29 Sep 2026
Origin
Not publishedUnited States
Input → output
Not publishedText, image → text

Full datasheets, every price and sourceGPT-6.1 Sol ↗

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 Fable 5.2 77.2/100Rank 2/53

Survived 3 of 3
Foresight: complete playing field
Level 318 ptsTurn 20 / 20

GPT-6.1 Sol 62.0/100Rank 10/53

Survived 2 of 3
Foresight: complete playing field
Level 318 ptsTurn 20 / 20

Points per level

LevelClaude Fable 5.2GPT-6.1 Sol
Level 1Second Thoughts
27 ptsSurvived
26 ptsSurvived
Level 2Pressure Pot
12 ptsSurvived
6 ptsOut of lives
Level 3Hide or Flight
18 ptsSurvived
18 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 Fable 5.2 100.0/100Rank 1/54

Cleared 5 of 5
Latch: complete playing field
Level 520.8 ptsTurn 26 / 40

GPT-6.1 Sol 87.6/100Rank 2/54

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

Points per level

LevelClaude Fable 5.2GPT-6.1 Sol
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10.2 ptsClearedFinished early · 1 beacon left
10.2 ptsClearedFinished early · 1 beacon left
Level 3Relay vault
19.2 ptsCleared
19.2 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
18.2 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
20.8 ptsCleared
20.6 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

Claude Fable 5.2

The composition closely preserves the principal camera relationships. Visible cyan contact, elongated crimson coating and separate airborne black paint support the required interaction sequence, with a small crimson transport overshoot. Correct broad mirror placement coexists with major omissions in nested spherical imagery and simplified emitter mapping. Core score: 105.5/170; floor-damage reward: 0/10; combined total: 105.5/180.

GPT-6.1 Sol

Recognizable first sphere images and several central planar lights provide limited geometric agreement. Missing outer chains, truncated panel sequences and simplified interiors across the main, side and floor spheres leave most of the recursive reflection structure unsupported.

Score breakdown

CategoryClaude Fable 5.2GPT-6.1 Sol
State at 600 ms24.0/2524.0/25
Camera and placement15.0/1515.0/15
Reflections80.0/12035.0/120
Materials and scale8.5/1010.0/10
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 Fable 5.2

The compact mantle, eight curling rays and quiet face closely realize the requested living emblem. Controlled arm contours, coherent overlaps and restrained ornament give the design character. Shallow depth, ribbon-like arm modeling and repeated highlight bands limit anatomical and lighting complexity without compromising the intact silhouette.

GPT-6.1 Sol

Six outward-facing heads and evenly arranged loops make the pale interlocking knot immediately readable. Uniform widths, angular inner bends and fine scales preserve its ornamental geometry. The bodies feel more like textured tubes than living muscle: shading is subdued, crossing contact shadows are weak, and visible curved seams interrupt surface continuity. Small heads have readable eyes and jaws but limited anatomical depth.

Score breakdown

CategoryClaude Fable 5.2GPT-6.1 Sol
Task & likeness9.0/108.5/10
Anatomy & construction7.5/107.5/10
Space & placement7.0/108.0/10
Light & reflections7.0/107.0/10
Purposeful detail6.5/107.5/10
Artistry & character6.5/107.5/10
Materials & effects7.0/107.0/10
Visual integrity8.5/108.0/10

Benchmark task

Claude Fable 5.2

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

GPT-6.1 Sol

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

Same task instructions

Precise visual recall and portrait reconstruction.

The judgment

Claude Fable 5.2

A developed illustrative portrait with controlled facial shading, connected limbs, layered scenery and distinct aged-paint and gold effects. Its frontal torso, conspicuous smile and flattened fingers limit replication and anatomical precision. Decorative finish is stronger than the underlying seated construction.

GPT-6.1 Sol

The recognizable pose, dark clothing and misty landscape form a coherent portrait. Soft facial shading creates volume, but the broad face, outlined eyes and simplified smile limit likeness. Overlapping hands have flattened fingers and ambiguous separation. Angular landscape shapes and sparse fabric detail keep the execution competent rather than masterful.

Score breakdown

CategoryClaude Fable 5.2GPT-6.1 Sol
Task & likeness6.5/106.5/10
Anatomy & construction6.0/105.5/10
Space & placement6.0/106.5/10
Light & reflections6.5/106.5/10
Purposeful detail6.0/105.5/10
Artistry & character6.5/106.5/10
Materials & effects7.5/106.0/10
Visual integrity7.5/107.0/10

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 Fable 5.2

A lively sunset beach with clear playful activity, purposeful small details and developed water reflections. Layering and supported placements hold the scene together. Schematic anatomy and the turtle's overhead viewpoint limit construction, space and artistry, while atmospheric and surface effects show greater refinement.

GPT-6.1 Sol

A cohesive sunset palette, sweeping shoreline and framing palm create an appealing beach illustration. Animals, birds, play and a prominent sun reflection fulfill the brief. Connected but schematic figures and simplified dolphin anatomy limit construction; stepped reflections and mostly flat surfaces limit lighting and material depth. Small beach accessories remain readable and edges are clean.

Score breakdown

CategoryClaude Fable 5.2GPT-6.1 Sol
Task & likeness9.0/108.5/10
Anatomy & construction8.0/107.5/10
Space & placement7.5/107.5/10
Light & reflections8.5/107.5/10
Purposeful detail8.5/107.5/10
Artistry & character8.0/107.0/10
Materials & effects7.5/107.0/10
Visual integrity8.0/108.5/10

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 Fable 5.2

This benchmark has not been assessed yet.

GPT-6.1 Sol

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 Fable 5.2

A controlled action illustration with expressive animals, demonstrated riding and steering, and an energetic layered wake. Purposeful small features and articulated poses strengthen the drawing. Simplified extremities, shallow character volume and limited physical lighting remain its principal constraints.

GPT-6.1 Sol

The masked raccoon rides the dog's back, and the dog's forepaw meets a handlebar connected to the deck. Expressive faces, a striped tail and sweeping wake create an appealing composition. Overlapping bodies compress the seating and rear-leg anatomy; hull depth and sunset illumination remain schematic.

Score breakdown

CategoryClaude Fable 5.2GPT-6.1 Sol
Task & likeness8.5/108.5/10
Anatomy & construction8.0/107.5/10
Space & placement7.5/107.5/10
Light & reflections7.0/106.5/10
Purposeful detail8.5/108.0/10
Artistry & character8.0/108.0/10
Materials & effects7.5/107.5/10
Visual integrity8.0/108.5/10

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

Claude Fable 5.2

A strong illustration with an expressive pelican, readable riding contacts and carefully constructed bicycle details. Layered plumage, basket weave and coastal scenery reward inspection. Continuous attachments support the action, while limited visible leg articulation, modest volume and weakly directional foreground lighting constrain physical sophistication.

GPT-6.1 Sol

A clearly recognizable pelican rides a well-composed bicycle through a warm coastal scene. The expressive bill, restrained palette and carefully drawn wheels give the illustration character. Leg-to-pedal connections are less convincing, especially the obscured far foot. Lighting provides gentle volume but little directional shadow. The small subtitle is clipped at the lower border.

Score breakdown

CategoryClaude Fable 5.2GPT-6.1 Sol
Task & likeness9.0/109.0/10
Anatomy & construction8.0/107.0/10
Space & placement7.5/108.0/10
Light & reflections6.5/107.0/10
Purposeful detail8.0/108.0/10
Artistry & character7.5/108.5/10
Materials & effects7.0/107.5/10
Visual integrity8.0/108.0/10

Benchmark task

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