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Claude Sonnet 5.5 vs Union Alpha

Claude Sonnet 5.5 scores 2.7 points higher overall (62.7 vs 60.0). Claude Sonnet 5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections. Union Alpha’s overall score includes one estimated scene.

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Overall StealthMark

62.7/100
60.0/100Estimated · 1 missing scene

General Intelligence

45.2/100
40.9/100Partial coverage

Visual Intelligence

76.1/100
73.2/100Partial coverage

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.

Union Alpha38.3/100

Union Alpha: Newton's Mirror SVG benchmark
Researcher observations

Recognizable near-field sphere placement and bilateral convergence provide limited optical structure. Broad gray regions interrupt lateral sightlines and truncate side-floor images. Missing outer chains, absent nested sphere imagery and incomplete planar and curved emitter mappings dominate the reflection system.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Sonnet 5.5Union Alpha
State at 600 ms25.0/2525.0/25
Camera and placement15.0/1515.0/15
Reflections23.5/12019.0/120
Materials and scale10.0/1010.0/10
Floor-damage reward0.0/100.0/10

Selfie

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.

Compare category scores
CategoryClaude Sonnet 5.5Union Alpha
Prompt & likeness8.0/10—
Anatomy & construction8.0/10—
Space & placement8.0/10—
Light & reflections7.5/10—
Purposeful detail7.5/10—
Artistry & character8.0/10—
Materials & effects7.0/10—
Visual integrity8.5/10—

Beach

Different prompts

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

Union Alpha80.0/100

A beach at sunset with a palm tree, turtle, crab, birds, and a leaping dolphin.
Researcher observations

A cohesive sunset palette, sweeping shoreline and playful animals make an appealing beach illustration. The sun’s reflection establishes a clear focal axis, balanced by the palm and umbrella. Clean silhouettes and small decorative features reward inspection, though simplified anatomy, repetitive reflection bars and generic oval shadows limit volume and naturalism.

Exact prompt

Create an SVG of a amazing beach scene. Sunset, animals, fun, birds, reflections

Compare category scores
CategoryClaude Sonnet 5.5Union Alpha
Prompt & likeness9.0/109.0/10
Anatomy & construction7.0/107.5/10
Space & placement8.5/108.0/10
Light & reflections7.5/107.5/10
Purposeful detail9.0/108.0/10
Artistry & character9.5/108.0/10
Materials & effects7.5/107.0/10
Visual integrity7.5/108.5/10

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

Union Alpha64.0/100

An SVG interpretation of the Mona Lisa, with folded hands and a landscape background.
Researcher observations

The centered portrait, folded hands, dark clothing and hazy landscape clearly evoke the Mona Lisa. Muted colors and soft facial shading create a coherent illustration, but replication remains schematic: the face is broad, eyes outlined, smile simplified and overlapping fingers poorly resolved. Angular landscape shapes and flat fabric limit depth and painterly richness.

Exact prompt

Replicate mona-lisa as SVG

Compare category scores
CategoryClaude Sonnet 5.5Union Alpha
Prompt & likeness7.0/107.0/10
Anatomy & construction6.0/106.0/10
Space & placement6.5/106.5/10
Light & reflections6.5/106.5/10
Purposeful detail6.0/105.5/10
Artistry & character6.5/106.5/10
Materials & effects5.5/105.0/10
Visual integrity6.5/107.5/10

Raccoon

Different prompts

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

Union Alpha72.0/100

A raccoon rides on a dog as the dog steers a red jet ski.
Researcher observations

Expressive animals, a readable riding arrangement and sweeping spray create an appealing cartoon. The raccoon sits convincingly on the dog's back, but the dog's paw does not clearly grip the handlebar, whose connection to the hull is unresolved. Flat lighting provides little volume or reflection. A dark rectangular strip interrupts the upper-right background.

Exact prompt

A raccoon sits on a dog's back while the dog steers a jet ski

Compare category scores
CategoryClaude Sonnet 5.5Union Alpha
Prompt & likeness8.5/108.0/10
Anatomy & construction7.0/106.5/10
Space & placement7.5/107.5/10
Light & reflections6.5/105.5/10
Purposeful detail8.0/107.5/10
Artistry & character8.0/108.0/10
Materials & effects7.5/107.5/10
Visual integrity8.0/107.0/10

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

Union Alpha73.8/100

A pelican riding a teal bicycle beneath a sunny blue sky.
Researcher observations

The pelican is immediately recognizable, with an expressive face, convincing bill silhouette and appealing pastel composition. Both legs connect to feet, and the wing reaches the handlebar. Bicycle construction is less resolved: the far pedal lacks a clear crank connection and no chain is visible. Clean contours and orderly spokes support the illustration, while flat lighting and simplified surfaces limit depth.

Exact prompt

Generate an SVG of a pelican riding a bicycle

Compare category scores
CategoryClaude Sonnet 5.5Union Alpha
Prompt & likeness9.0/108.5/10
Anatomy & construction7.5/106.5/10
Space & placement7.5/107.5/10
Light & reflections6.5/106.0/10
Purposeful detail8.0/107.0/10
Artistry & character7.5/108.0/10
Materials & effects6.5/106.5/10
Visual integrity8.0/108.5/10