STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Claude Sonnet 5.5 vs GPT 5.6 Terra

Claude Sonnet 5.5 scores 11.6 points higher overall (62.7 vs 51.1). Claude Sonnet 5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

62.7/100
51.1/100

General Intelligence

45.2/100
31.1/100

Visual Intelligence

76.1/100
66.2/100

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 5.6 Terra23.3/100

GPT 5.6 Terra: Newton's Mirror SVG benchmark
Researcher observations

The real sphere and airborne black blob are substantially too low in the complete frame after accounting for aspect ratio. The first wall and floor reflections have incompatible placement, relative size or silhouette. Both lateral regions lack the references' receding lane-and-chain organization. The few recognizable mirror images provide limited optical structure. The main, side and floor spheres replace nested mirror imagery with smooth bands, while sparse planar light patches and broad spherical highlights fail to establish coherent repeated emitter mapping.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Terra
State at 600 ms25.0/2523.5/25
Camera and placement15.0/156.0/15
Reflections23.5/1207.0/120
Materials and scale10.0/105.5/10
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 5.6 Terra73.0/100

GPT 5.6 Terra: Selfie SVG benchmark
Researcher observations

Six ivory heads and rounded lobes create a striking radial emblem around a clear hexagonal opening. Soft shading gives the bodies volume, but abrupt rectangular and diagonal band endings make the continuous alternating weave ambiguous. Repetitive scale lines and simplified faces convey an ornamental serpent more convincingly than living anatomy.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Terra
Prompt & likeness8.0/107.5/10
Anatomy & construction8.0/106.5/10
Space & placement8.0/107.5/10
Light & reflections7.5/107.5/10
Purposeful detail7.5/107.0/10
Artistry & character8.0/108.0/10
Materials & effects7.0/107.0/10
Visual integrity8.5/107.5/10

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 5.6 Terra73.3/100

GPT 5.6 Terra: Beach SVG benchmark
Researcher observations

Warm sunset gradients, framing palms and colorful beach activities create an appealing scene. Animals, birds and a sun reflection fulfill the brief. The dog and turtle remain schematic, foreground depth is shallow, and the reflection forms rigid bands. Clean silhouettes and readable accessories support a competent illustration, but limited anatomy, material variation and lighting keep it below exceptional.

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 5.6 Terra
Prompt & likeness9.0/108.5/10
Anatomy & construction7.0/107.0/10
Space & placement8.5/107.0/10
Light & reflections7.5/106.5/10
Purposeful detail9.0/107.0/10
Artistry & character9.5/107.5/10
Materials & effects7.5/106.5/10
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 5.6 Terra49.5/100

GPT 5.6 Terra: Mona Lisa SVG benchmark
Researcher observations

The dark clothing, central portrait and restrained smile evoke the Mona Lisa, but replication is limited by the broad face, elongated neck, nearly frontal pose and indistinct landscape. Soft gradients give the face some volume. Crossed arms become rounded masses without readable fingers or wrists, and the expression lacks the original's subtlety. Clean framing and curves support an otherwise basic, uneven portrait.

Exact prompt

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

Compare category scores
CategoryClaude Sonnet 5.5GPT 5.6 Terra
Prompt & likeness7.0/105.0/10
Anatomy & construction6.0/104.0/10
Space & placement6.5/105.5/10
Light & reflections6.5/106.0/10
Purposeful detail6.0/103.5/10
Artistry & character6.5/105.0/10
Materials & effects5.5/104.5/10
Visual integrity6.5/106.5/10

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 5.6 Terra72.0/100

GPT 5.6 Terra: Raccoon SVG benchmark
Researcher observations

Expressive faces, a recognizable raccoon perched on the dog, and a sweeping wake make an appealing cartoon. The principal weakness is the steering interaction: the dog's paw sits beside the control assembly without a convincing handlebar grip. Bold outlines and coherent layering provide polish, while simplified shading, compressed seating geometry and angular splashes limit depth and physical credibility.

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 5.6 Terra
Prompt & likeness8.5/107.5/10
Anatomy & construction7.0/106.0/10
Space & placement7.5/107.5/10
Light & reflections6.5/106.5/10
Purposeful detail8.0/107.5/10
Artistry & character8.0/108.0/10
Materials & effects7.5/107.0/10
Visual integrity8.0/108.0/10

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

GPT 5.6 Terra70.5/100

GPT 5.6 Terra: Pelican SVG benchmark
Researcher observations

The oversized bill, expressive eye and balanced twilight palette make the cyclist immediately readable. Clean contours and wheel details support the illustration, but the rabbit-like head tufts weaken pelican likeness. The wing does not clearly grip the handlebar, pedal contact is uneven, and the drivetrain is incomplete. Lighting remains mostly decorative.

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 5.6 Terra
Prompt & likeness9.0/108.0/10
Anatomy & construction7.5/106.0/10
Space & placement7.5/107.0/10
Light & reflections6.5/106.5/10
Purposeful detail8.0/107.0/10
Artistry & character7.5/107.5/10
Materials & effects6.5/106.5/10
Visual integrity8.0/108.0/10