STEALTHMARK · HEAD TO HEAD

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Claude Sonnet 5.5 vs GPT 5.5

Claude Sonnet 5.5 scores 20.7 points higher overall (62.7 vs 42.0). 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
42.0/100

General Intelligence

45.2/100
26.2/100

Visual Intelligence

76.1/100
53.4/100

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 5.520.8/100

GPT 5.5: Newton's Mirror SVG benchmark
Researcher observations

The paint ordering and separate black bead support part of the physical state, but adhesion and rotational transport remain only partly established. The sweeping cyan arc and long crimson lobes do not clearly communicate the limited time since their respective impacts. The main sphere is too large and too low, and the black bead is below its required projected position. Displaced isolated sphere images, a flattened floor echo and missing recursive, nested and emitter reflections provide little coherent optical structure. The colored paint is excessively bulky for the specified quantities.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.5
State at 600 ms25.0/2519.5/25
Camera and placement15.0/157.0/15
Reflections23.5/1205.0/120
Materials and scale10.0/106.0/10
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 5.542.8/100

GPT 5.5: Selfie SVG benchmark
Researcher observations

Six pale, scaled lobes form a balanced radial arrangement, but they remain separate capsules rather than an interlocking serpent knot. There are no crossings, alternating overlaps, or crisp inner bends; the central hexagon is an isolated outline. Small outward-facing heads sit within the lobes without integrated necks. Soft shading and tidy contours provide some finish, while repetitive oval scales and cartoon faces limit organic credibility.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.5
Prompt & likeness8.0/102.5/10
Anatomy & construction8.0/103.0/10
Space & placement8.0/105.0/10
Light & reflections7.5/105.0/10
Purposeful detail7.5/104.5/10
Artistry & character8.0/104.5/10
Materials & effects7.0/104.5/10
Visual integrity8.5/107.0/10

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 5.563.3/100

GPT 5.5: Beach SVG benchmark
Researcher observations

The sunset, palms, birds, playful animals and ball clearly establish the requested beach scene. Warm sky gradients and clean silhouettes make it appealing. Animal construction remains basic, especially the round-eared foreground figure's unclear torso and limbs. The dolphin lacks a convincing splash, and broad reflection bands suggest sunset light without resolving its behavior on water.

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 5.5
Prompt & likeness9.0/108.0/10
Anatomy & construction7.0/105.5/10
Space & placement8.5/106.0/10
Light & reflections7.5/106.0/10
Purposeful detail9.0/105.0/10
Artistry & character9.5/106.5/10
Materials & effects7.5/105.0/10
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 5.552.5/100

GPT 5.5: Mona Lisa SVG benchmark
Researcher observations

The dark veil, restrained smile, crossed hands and muted landscape establish Mona Lisa references. Replication is limited by the oversized frontal face, simplified eyes and hands drawn as overlapping tapered shapes without fingers. Clean contours and a balanced frame support the composition, but broad landscape bands, sparse garment detail and shallow shading leave the portrait basic rather than masterful.

Exact prompt

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

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.5
Prompt & likeness7.0/106.0/10
Anatomy & construction6.0/104.5/10
Space & placement6.5/105.5/10
Light & reflections6.5/105.0/10
Purposeful detail6.0/103.5/10
Artistry & character6.5/105.5/10
Materials & effects5.5/104.0/10
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 5.556.0/100

GPT 5.5: Raccoon SVG benchmark
Researcher observations

The raccoon's masked face, bright hull and sweeping wake make the scene readable and lively. The dog is much less resolved: its head is ambiguous, overlapping brown forms obscure its anatomy, and its paws do not visibly grip the controls. Smooth shapes and cheerful colors provide appeal, but weak steering construction and limited depth keep the drawing uneven.

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 5.5
Prompt & likeness8.5/106.0/10
Anatomy & construction7.0/104.0/10
Space & placement7.5/106.0/10
Light & reflections6.5/105.5/10
Purposeful detail8.0/105.5/10
Artistry & character8.0/106.5/10
Materials & effects7.5/105.5/10
Visual integrity8.0/106.5/10

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 5.564.3/100

GPT 5.5: Pelican SVG benchmark
Researcher observations

The oversized bill, bright bicycle and sunset create an appealing, recognizable cartoon. Riding mechanics are less convincing: the wing has no clear steering contact, leg attachments are uneven, and feet do not visibly engage pedals. A dark notch complicates the rear neck junction. Clean contours and orderly spokes provide polish, while simplified anatomy and lighting limit depth.

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 5.5
Prompt & likeness9.0/107.5/10
Anatomy & construction7.5/104.5/10
Space & placement7.5/106.5/10
Light & reflections6.5/106.5/10
Purposeful detail8.0/106.0/10
Artistry & character7.5/107.5/10
Materials & effects6.5/106.0/10
Visual integrity8.0/107.5/10