STEALTHMARK · HEAD TO HEAD

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GPT 5.5 vs Union Alpha

Union Alpha scores 18.0 points higher overall (60.0 vs 42.0). Union Alpha 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

42.0/100
60.0/100Estimated · 1 missing scene

General Intelligence

26.2/100
40.9/100Partial coverage

Visual Intelligence

53.4/100
73.2/100Partial coverage

Newton's Mirror

Same prompt

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

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.

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
CategoryGPT 5.5Union Alpha
State at 600 ms19.5/2525.0/25
Camera and placement7.0/1515.0/15
Reflections5.0/12019.0/120
Materials and scale6.0/1010.0/10
Floor-damage reward0.0/100.0/10

Selfie

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
CategoryGPT 5.5Union Alpha
Prompt & likeness2.5/10—
Anatomy & construction3.0/10—
Space & placement5.0/10—
Light & reflections5.0/10—
Purposeful detail4.5/10—
Artistry & character4.5/10—
Materials & effects4.5/10—
Visual integrity7.0/10—

Beach

Different prompts

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

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
CategoryGPT 5.5Union Alpha
Prompt & likeness8.0/109.0/10
Anatomy & construction5.5/107.5/10
Space & placement6.0/108.0/10
Light & reflections6.0/107.5/10
Purposeful detail5.0/108.0/10
Artistry & character6.5/108.0/10
Materials & effects5.0/107.0/10
Visual integrity8.0/108.5/10

Mona Lisa

Different prompts

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

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
CategoryGPT 5.5Union Alpha
Prompt & likeness6.0/107.0/10
Anatomy & construction4.5/106.0/10
Space & placement5.5/106.5/10
Light & reflections5.0/106.5/10
Purposeful detail3.5/105.5/10
Artistry & character5.5/106.5/10
Materials & effects4.0/105.0/10
Visual integrity7.5/107.5/10

Raccoon

Different prompts

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

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
CategoryGPT 5.5Union Alpha
Prompt & likeness6.0/108.0/10
Anatomy & construction4.0/106.5/10
Space & placement6.0/107.5/10
Light & reflections5.5/105.5/10
Purposeful detail5.5/107.5/10
Artistry & character6.5/108.0/10
Materials & effects5.5/107.5/10
Visual integrity6.5/107.0/10

Pelican

Benchmax control

Outside General and Visual Intelligence.

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

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
CategoryGPT 5.5Union Alpha
Prompt & likeness7.5/108.5/10
Anatomy & construction4.5/106.5/10
Space & placement6.5/107.5/10
Light & reflections6.5/106.0/10
Purposeful detail6.0/107.0/10
Artistry & character7.5/108.0/10
Materials & effects6.0/106.5/10
Visual integrity7.5/108.5/10