STEALTHMARK · HEAD TO HEAD

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Claude Opus 5.5 vs GPT 5.6 Sol

Claude Opus 5.5 scores 11.3 points higher overall (66.0 vs 54.7). 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
54.7/100

General Intelligence

55.3/100
33.4/100

Visual Intelligence

74.5/100
71.3/100

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 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 Opus 5.5GPT 5.6 Sol
State at 600 ms25.0/2524.0/25
Camera and placement15.0/156.0/15
Reflections46.5/12011.0/120
Materials and scale8.0/1010.0/10
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 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 Opus 5.5GPT 5.6 Sol
Prompt & likeness8.0/107.5/10
Anatomy & construction7.5/106.5/10
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 & effects7.5/104.5/10
Visual integrity8.5/106.0/10

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 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 Opus 5.5GPT 5.6 Sol
Prompt & likeness8.5/108.5/10
Anatomy & construction7.5/107.0/10
Space & placement7.0/107.0/10
Light & reflections8.0/107.5/10
Purposeful detail8.0/107.5/10
Artistry & character8.0/108.0/10
Materials & effects6.5/107.0/10
Visual integrity8.5/108.0/10

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 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 Opus 5.5GPT 5.6 Sol
Prompt & likeness7.0/107.0/10
Anatomy & construction6.0/105.5/10
Space & placement6.5/106.5/10
Light & reflections6.0/106.5/10
Purposeful detail6.5/106.0/10
Artistry & character6.5/106.5/10
Materials & effects6.5/106.0/10
Visual integrity7.0/107.5/10

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 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 Opus 5.5GPT 5.6 Sol
Prompt & likeness8.5/108.5/10
Anatomy & construction7.0/107.0/10
Space & placement7.5/107.5/10
Light & reflections6.0/106.5/10
Purposeful detail7.5/108.0/10
Artistry & character8.0/108.0/10
Materials & effects7.0/107.5/10
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 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 Opus 5.5GPT 5.6 Sol
Prompt & likeness8.5/109.0/10
Anatomy & construction6.5/104.5/10
Space & placement7.0/107.5/10
Light & reflections6.0/107.0/10
Purposeful detail7.5/107.5/10
Artistry & character7.5/108.0/10
Materials & effects6.0/107.0/10
Visual integrity8.5/105.5/10