STEALTHMARK · HEAD TO HEAD

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Claude Opus 5.5 vs GPT 6 Luna

Claude Opus 5.5 scores 16.7 points higher overall (66.0 vs 49.3). Claude Opus 5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections.

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Overall StealthMark

66.0/100
49.3/100

General Intelligence

55.3/100
28.2/100

Visual Intelligence

74.5/100
65.1/100

Newton's Mirror

Same prompt

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

Claude Opus 5.552.5/100

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

Open lateral sightlines, first reflected silhouettes and near-field planar panel placement are convincing. Missing outer chains, truncated repetitions and absent nested spherical room and emitter imagery remain the main weaknesses.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

GPT 6 Luna20.8/100

GPT 6 Luna: Newton's Mirror SVG benchmark
Researcher observations

The schematic scene supports the paint contact order and compact paint scale. Its low, undersized main sphere and incorrectly placed wall images depart from the reference geometry. A few shrinking wall images provide limited optical organization, while absent lateral recursion and outer chains, broad sphere ribbons and isolated panel highlights leave most nested room and emitter mapping undeveloped.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Opus 5.5GPT 6 Luna
State at 600 ms25.0/2522.0/25
Camera and placement15.0/153.5/15
Reflections46.5/1205.0/120
Materials and scale8.0/107.0/10
Floor-damage reward0.0/100.0/10

Selfie

Different prompts

Claude Opus 5.578.3/100

Claude Opus 5.5: Selfie SVG benchmark
Researcher observations

The centered coral squid has a friendly, restrained expression and a balanced radial silhouette within a cream arch. Smooth curves and soft shading give it an appealing matte finish. The mantle is more elongated than compact, the upper arms are visually ambiguous, and the two hanging tentacles read somewhat like legs. Clean execution supports a strong stylized illustration.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

GPT 6 Luna47.3/100

GPT 6 Luna: Selfie SVG benchmark
Researcher observations

Sixfold symmetry, pale coloring and six outward-facing heads establish the motif. However, every neck floats clear of the knot. Squared outer sections replace the required semicircular lobes, and the large stepped opening lacks a regular hexagonal contour. Repeated scales and soft shading suggest skin, but translucent crossings and doubled edges weaken the living, interwoven construction.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Opus 5.5GPT 6 Luna
Prompt & likeness8.0/104.5/10
Anatomy & construction7.5/103.5/10
Space & placement8.0/105.5/10
Light & reflections7.5/105.0/10
Purposeful detail7.5/105.0/10
Artistry & character8.0/105.5/10
Materials & effects7.5/105.0/10
Visual integrity8.5/104.5/10

Beach

Same prompt

Claude Opus 5.578.0/100

Claude Opus 5.5: Beach SVG benchmark
Researcher observations

A lively, well-composed beach illustration with rich sunset colors, recognizable animals and appealing accessories. The sun reflection establishes a strong central focus. Clean silhouettes and small details reward inspection, though simplified animal construction, uneven contact shadows and mostly flat materials limit depth and realism.

Exact prompt

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

GPT 6 Luna76.8/100

GPT 6 Luna: Beach SVG benchmark
Researcher observations

The warm sky, layered sea and framing palms create an appealing composition. Animals, birds, beach activities and a sun reflection fulfill the brief. People have schematic joints and indistinct hands and feet; the airborne dolphin lacks a splash. Limited shadows and surface modeling weaken depth, while clean silhouettes and thoughtful small details support the illustration.

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 Opus 5.5GPT 6 Luna
Prompt & likeness8.5/109.0/10
Anatomy & construction7.5/107.0/10
Space & placement7.0/107.5/10
Light & reflections8.0/106.5/10
Purposeful detail8.0/107.5/10
Artistry & character8.0/108.0/10
Materials & effects6.5/107.0/10
Visual integrity8.5/108.5/10

Mona Lisa

Same prompt

Claude Opus 5.564.8/100

Claude Opus 5.5: Mona Lisa SVG benchmark
Researcher observations

The portrait preserves the recognizable composition, dark veil, folded hands and distant landscape. Replication is limited by the elongated face and neck, conspicuous eyes and simplified smile. Hands remain connected but their rounded fingers and wrists lack convincing anatomy. Restrained colors create cohesion; shallow modeling and pervasive mottling weaken volume and painterly subtlety.

Exact prompt

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

GPT 6 Luna65.5/100

GPT 6 Luna: Mona Lisa SVG benchmark
Researcher observations

The dark veil, crossed arms, restrained smile and layered landscape clearly evoke Mona Lisa. Clean contours and muted colors create a coherent illustration. Replication is limited by enlarged, outlined eyes, simplified facial volume, broad shoulders and indistinct overlapping hands. Gradients suggest depth, but lack the original's subtle painterly transitions.

Exact prompt

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

Compare category scores
CategoryClaude Opus 5.5GPT 6 Luna
Prompt & likeness7.0/107.0/10
Anatomy & construction6.0/106.0/10
Space & placement6.5/107.0/10
Light & reflections6.0/106.0/10
Purposeful detail6.5/106.0/10
Artistry & character6.5/106.5/10
Materials & effects6.5/105.5/10
Visual integrity7.0/108.0/10

Raccoon

Same prompt

Claude Opus 5.575.0/100

Claude Opus 5.5: Raccoon SVG benchmark
Researcher observations

The masked raccoon clearly rides the dog's back, and the dog's forward paw reaches the steering grip. Expressive faces, vivid colors and sweeping wakes create an appealing illustration. Connected limbs remain schematic, as does the small steering assembly. The broad hull and flat foam weaken water contact; the glowing sun lacks a corresponding reflection or convincing cast shadows.

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 6 Luna72.5/100

GPT 6 Luna: Raccoon SVG benchmark
Researcher observations

Expressive faces, warm sunset colors and clean silhouettes create an appealing illustration. The raccoon sits on the dog's back, but the dog's grip and steering linkage remain unclear. The broad hull resembles a speedboat, and flat shading, absent sun reflections and modest water displacement limit depth and motion.

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 Opus 5.5GPT 6 Luna
Prompt & likeness8.5/108.0/10
Anatomy & construction7.0/106.5/10
Space & placement7.5/107.5/10
Light & reflections6.0/106.0/10
Purposeful detail7.5/107.0/10
Artistry & character8.0/108.0/10
Materials & effects7.0/106.5/10
Visual integrity8.0/108.0/10

Pelican

Benchmax control

Outside General and Visual Intelligence.

Claude Opus 5.572.5/100

Claude Opus 5.5: Pelican SVG benchmark
Researcher observations

The recognizable pelican, orderly bicycle wheels and harmonious sunset create an appealing illustration. Both legs connect to the body and reach pedals; no clear detached or inverted parts appear. Steering contact and seating support are less convincing, while the drivetrain remains schematic. Crisp outlines give a clean finish, but limited shading and flat surfaces leave the scene with modest depth.

Exact prompt

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

GPT 6 Luna71.0/100

GPT 6 Luna: Pelican SVG benchmark
Researcher observations

The pelican’s distinctive bill and the coordinated vintage poster palette make an appealing illustration. Circular wheels, orderly spokes and clean lettering strengthen the design. Riding mechanics are less convincing: neither wing reaches the handlebars, pedal contact is ambiguous, and the drivetrain is incomplete. The wheels sit against water without a clear supporting surface. Flat lighting limits volume.

Exact prompt

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

Compare category scores
CategoryClaude Opus 5.5GPT 6 Luna
Prompt & likeness8.5/108.0/10
Anatomy & construction6.5/106.0/10
Space & placement7.0/106.5/10
Light & reflections6.0/106.5/10
Purposeful detail7.5/107.5/10
Artistry & character7.5/108.0/10
Materials & effects6.0/106.5/10
Visual integrity8.5/108.0/10