STEALTHMARK · HEAD TO HEAD

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Claude Sonnet 5.5 vs GPT 5.6 Sol

Claude Sonnet 5.5 scores 8.0 points higher overall (62.7 vs 54.7). Claude Sonnet 5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections.

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Overall StealthMark

62.7/100
54.7/100

General Intelligence

45.2/100
33.4/100

Visual Intelligence

76.1/100
71.3/100

Newton's Mirror

Same prompt

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

Claude Sonnet 5.540.8/100

Claude Sonnet 5.5: Newton's Mirror SVG benchmark
Researcher observations

The near-field silhouettes, broad perspective and paint contact order are recognizable. Missing outer chains, truncated repetitions and absent ordered imagery within the main and reflected spheres substantially limit the reflection system. Sparse spherical highlights leave much of the curved room and emitter mapping unsupported, despite some plausible planar light sequences.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

GPT 5.6 Sol28.3/100

GPT 5.6 Sol: Newton's Mirror SVG benchmark
Researcher observations

The central sphere and paint ordering are supported, but a frontal, centrally converging chamber replaces the required corner perspective. The first wall and floor images have incorrect placement and scale relationships. Sparse reflection cues remain, while continuous outer chains, open lateral sightlines, dense planar light sequences and curved nested spherical imagery are largely missing.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Sol
State at 600 ms25.0/2524.0/25
Camera and placement15.0/156.0/15
Reflections23.5/12011.0/120
Materials and scale10.0/1010.0/10
Floor-damage reward0.0/100.0/10

Selfie

Different prompts

Claude Sonnet 5.579.0/100

Claude Sonnet 5.5: Selfie SVG benchmark
Researcher observations

The centered coral squid has a friendly, composed expression and a balanced flower-like silhouette. Eight thick arms and two slender tentacles remain visibly connected, with no inverted parts. The mantle is elongated rather than compact, and the arm spacing is uneven. Soft shading gives volume, but dense stippling weakens the requested smooth matte finish; the broad background halo makes depth less precise.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

GPT 5.6 Sol64.5/100

GPT 5.6 Sol: Selfie SVG benchmark
Researcher observations

Six evenly spaced lobes, outward-facing heads and a clear central hexagon establish the requested knot. The ivory silhouette is controlled, but broad crossing bands resemble rigid strips, shading provides limited muscular volume, and repetitive scale lines extend across black loop openings. Small oval heads have readable eyes and mouths but limited anatomical character or moist surface detail.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Sol
Prompt & likeness8.0/107.5/10
Anatomy & construction8.0/106.5/10
Space & placement8.0/107.0/10
Light & reflections7.5/105.0/10
Purposeful detail7.5/106.0/10
Artistry & character8.0/107.0/10
Materials & effects7.0/104.5/10
Visual integrity8.5/106.0/10

Beach

Same prompt

Claude Sonnet 5.582.3/100

Claude Sonnet 5.5: Beach SVG benchmark
Researcher observations

A richly designed beach illustration combines radiant sunset bands, intricate palm fans and playful silhouettes within a cohesive purple, coral and turquoise palette. Carefully varied accessories reward close inspection, while overlapping foreground forms and shoreline layers organize the abundant activity. Dense palm strokes compete with focal subjects; animal anatomy, relative scales and reflected silhouettes remain simplified.

Exact prompt

Create an SVG of a amazing beach scene. Sunset, animals, fun, birds, reflections Make it a masterpiece, no tools allowed

GPT 5.6 Sol75.8/100

GPT 5.6 Sol: Beach SVG benchmark
Researcher observations

The purple-to-gold sunset, framing palms and varied beach activities create an appealing, coherent illustration. The sun’s reflection establishes a clear focal path. Figures and animals are recognizable but geometrically simplified; airborne dolphins lack convincing splashes, and the boat reflection is schematic. Clean silhouettes and playful details succeed more strongly than anatomical depth or material realism.

Exact prompt

Create an SVG of a amazing beach scene. Sunset, animals, fun, birds, reflections Make it a masterpiece, no tools allowed

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Sol
Prompt & likeness9.0/108.5/10
Anatomy & construction7.0/107.0/10
Space & placement8.5/107.0/10
Light & reflections7.5/107.5/10
Purposeful detail9.0/107.5/10
Artistry & character9.5/108.0/10
Materials & effects7.5/107.0/10
Visual integrity7.5/108.0/10

Mona Lisa

Different prompts

Claude Sonnet 5.563.8/100

Claude Sonnet 5.5: Mona Lisa SVG benchmark
Researcher observations

The crossed hands, dark dress, restrained smile and winding landscape clearly recall the Mona Lisa. Replication is limited by the frontal symmetry, wide eyes, elongated neck and flattened fingers. Soft facial shading provides volume, but heavy darkness and pervasive crackle obscure forms. The composition is coherent; the landscape and fabric remain visibly schematic.

Exact prompt

Replicate mona-lisa as SVG Make it a masterpiece, no tools allowed

GPT 5.6 Sol64.0/100

GPT 5.6 Sol: Mona Lisa SVG benchmark
Researcher observations

The crossed hands, dark dress and winding landscape establish the Mona Lisa composition. Replication is limited by enlarged eyes, an elongated face and a more frontal pose. Broad gradients suggest volume, but outlined features and flattened, overlapping fingers weaken the portrait. The frame and restrained palette unify the image; visible grain adds texture without convincing painterly transitions.

Exact prompt

Replicate mona-lisa as SVG Make it a masterpiece, no tools allowed

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Sol
Prompt & likeness7.0/107.0/10
Anatomy & construction6.0/105.5/10
Space & placement6.5/106.5/10
Light & reflections6.5/106.5/10
Purposeful detail6.0/106.0/10
Artistry & character6.5/106.5/10
Materials & effects5.5/106.0/10
Visual integrity6.5/107.5/10

Raccoon

Same prompt

Claude Sonnet 5.576.3/100

Claude Sonnet 5.5: Raccoon SVG benchmark
Researcher observations

The raccoon clearly rides on the dog's back while the dog grips the jet ski controls. Expressive faces, vivid colors and a sweeping wake make the scene appealing. Visible limbs connect coherently, but overlapping steering paws and an indistinct control mounting weaken construction. Flat character lighting and simplified water limit depth and material realism.

Exact prompt

Generate an SVG: A raccoon sits on a dog's back while the dog steers a jet ski Make it a masterpiece, no tools allowed

GPT 5.6 Sol76.3/100

GPT 5.6 Sol: Raccoon SVG benchmark
Researcher observations

Expressive faces, bold silhouettes and layered waves make an appealing cartoon. The raccoon sits convincingly behind the dog's shoulders, and the dog's forward paw reaches the steering grip. Steering construction and seated support remain somewhat ambiguous. The glowing sunset lacks a corresponding warm reflection or consistent illumination on the riders.

Exact prompt

Generate an SVG: A raccoon sits on a dog's back while the dog steers a jet ski Make it a masterpiece, no tools allowed

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Sol
Prompt & likeness8.5/108.5/10
Anatomy & construction7.0/107.0/10
Space & placement7.5/107.5/10
Light & reflections6.5/106.5/10
Purposeful detail8.0/108.0/10
Artistry & character8.0/108.0/10
Materials & effects7.5/107.5/10
Visual integrity8.0/108.0/10

Pelican

Benchmax control

Outside General and Visual Intelligence.

Claude Sonnet 5.576.8/100

Claude Sonnet 5.5: Pelican SVG benchmark
Researcher observations

The pelican is immediately recognizable, with an expressive face, generous bill and appealing cycling pose. Spokes, chain, feathers and scarf provide purposeful detail. The bicycle largely holds together, though overlapping angular legs obscure the far foot’s pedal contact. Clean outlines and balanced composition succeed; flat surfaces and limited directional lighting constrain depth.

Exact prompt

Generate an SVG of a pelican riding a bicycle Make it a masterpiece, no tools allowed

GPT 5.6 Sol69.3/100

GPT 5.6 Sol: Pelican SVG benchmark
Researcher observations

The expressive pelican and balanced coastal composition remain appealing, but a sky-colored slit between the neck contours above the wing leaves the central anatomy incoherent. This visible construction and layering defect prevents a clean-integrity assessment. Clustered feet lack clear pedal contacts and the chain routing is schematic; lighting and water reflections remain graphic.

Exact prompt

Generate an SVG of a pelican riding a bicycle Make it a masterpiece, no tools allowed

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Sol
Prompt & likeness9.0/109.0/10
Anatomy & construction7.5/104.5/10
Space & placement7.5/107.5/10
Light & reflections6.5/107.0/10
Purposeful detail8.0/107.5/10
Artistry & character7.5/108.0/10
Materials & effects6.5/107.0/10
Visual integrity8.0/105.5/10