STEALTHMARK · HEAD TO HEAD

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Claude Fable 5.1 vs GPT-6 Astra

GPT-6 Astra scores 6.6 points higher overall (68.7 vs 62.1). GPT-6 Astra scores higher on Newton's Mirror, with its largest category advantage in reflections.

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Overall StealthMark

62.1/100
68.7/100

General Intelligence

54.3/100
59.0/100

Visual Intelligence

67.7/100
76.1/100

Newton's Mirror

Same prompt

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

Claude Fable 5.151.7/100

Claude Fable 5.1: Newton's Mirror SVG benchmark
Researcher observations

The broad paint sequence, bilateral near-field sphere arrangement, overlaps and diminishing panel repetitions are recognizable; crimson is slightly too low. Small paint scale and basic shading provide material cues, although the steel response remains soft. Inaccurate light projections, missing outer chains and incomplete nested room imagery remain the principal limitations.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

GPT-6 Astra57.8/100

GPT-6 Astra: Newton's Mirror SVG benchmark
Researcher observations

Major placement and the visible contact sequence are convincing. Dense planar light repetition, recognizable spherical panel images and simplified nested sphere motifs provide useful optical structure. Missing outer chains, truncated distant sequences and incorrect bead-like belts still leave the recursive reflections substantially incomplete.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Fable 5.1GPT-6 Astra
State at 600 ms24.0/2525.0/25
Camera and placement14.0/1515.0/15
Reflections48.0/12054.0/120
Materials and scale7.0/1010.0/10
Floor-damage reward0.0/100.0/10

Selfie

Different prompts

Claude Fable 5.169.0/100

Claude Fable 5.1: Selfie SVG benchmark
Researcher observations

The coral palette, friendly face, matte shading and cream arch create a coherent emblem. However, the mantle is elongated rather than compact, and the appendages spread mostly sideways and downward instead of forming an evenly spaced, flower-like starburst. Two thin hanging appendages weaken the thick-arm motif. Clean contours and balanced framing support the simple design.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

GPT-6 Astra76.0/100

GPT-6 Astra: Selfie SVG benchmark
Researcher observations

The sixfold silhouette, pale coloring, outward heads and central hexagon closely match the brief. Fine scales and soft shading support rounded volume. However, several crossings have conspicuous rectangular seams and weak contact shadows, making the weave feel assembled. Small heads have limited anatomical definition, and the repetitive texture conveys less organic life than requested.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Fable 5.1GPT-6 Astra
Prompt & likeness6.5/108.5/10
Anatomy & construction6.5/107.5/10
Space & placement7.5/107.5/10
Light & reflections6.5/107.0/10
Purposeful detail6.0/107.5/10
Artistry & character7.5/108.0/10
Materials & effects6.5/107.0/10
Visual integrity8.0/107.0/10

Beach

Same prompt

Claude Fable 5.175.0/100

Claude Fable 5.1: Beach SVG benchmark
Researcher observations

The colorful sunset, layered shoreline, animals, kite and beach toys fulfill the lively beach brief. Clean silhouettes and a balanced composition give the illustration character. Construction is simplified: the umbrella resembles a segmented fan, dolphins have weak water interaction, and the sun’s reflection forms a rigid widening wedge. Flat surfaces and sparse contact shadows limit depth.

Exact prompt

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

GPT-6 Astra76.8/100

GPT-6 Astra: Beach SVG benchmark
Researcher observations

A coherent sunset beach illustration with an inviting palette, strong palm framing and a clear sun reflection. Animals, playing figures and beach equipment provide variety. Simplified human and dog anatomy, weak dolphin splash cues and uneven shadow directions limit physical conviction. Clean silhouettes and small decorative details support an appealing, polished composition.

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 Fable 5.1GPT-6 Astra
Prompt & likeness8.5/108.5/10
Anatomy & construction7.0/107.0/10
Space & placement7.0/107.5/10
Light & reflections7.0/107.5/10
Purposeful detail7.5/107.5/10
Artistry & character8.0/108.0/10
Materials & effects6.5/107.5/10
Visual integrity8.0/108.0/10

Mona Lisa

Same prompt

Claude Fable 5.156.5/100

Claude Fable 5.1: Mona Lisa SVG benchmark
Researcher observations

The dark clothing, crossed hands and hazy landscape establish the Mona Lisa composition. Replication is limited by the frontal, elongated face, wide eyes and simplified smile. Rounded, parallel fingers and unclear wrist transitions weaken the hands. Warm facial shading gives some volume, but broad garment shapes and scattered crack marks substitute for convincing folds and painterly detail.

Exact prompt

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

GPT-6 Astra67.3/100

GPT-6 Astra: Mona Lisa SVG benchmark
Researcher observations

The crossed hands, restrained smile, dark clothing and hazy landscape clearly recall the Mona Lisa. Replication is limited by the frontal, elongated face, schematic eyes and stiff fingers. Soft shading gives basic volume, but broad garment shapes and angular scenery lack the original’s nuanced depth and painterly transitions. The frame and composition are controlled; surface grain adds texture without resolving the simplified drawing.

Exact prompt

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

Compare category scores
CategoryClaude Fable 5.1GPT-6 Astra
Prompt & likeness6.0/107.0/10
Anatomy & construction5.0/106.0/10
Space & placement6.0/106.5/10
Light & reflections6.0/107.0/10
Purposeful detail5.0/106.5/10
Artistry & character5.5/107.0/10
Materials & effects5.5/107.0/10
Visual integrity6.5/107.5/10

Raccoon

Same prompt

Claude Fable 5.170.8/100

Claude Fable 5.1: Raccoon SVG benchmark
Researcher observations

The raccoon rides on the dog's back, and the dog's extended foreleg reaches the jet ski controls. Expressive faces, a clear silhouette and sweeping spray make the action readable. Limb and handlebar overlaps weaken construction; broad shading provides limited volume, and the glowing sun has little corresponding reflection on the water. Clean vector shapes support an appealing but simplified illustration.

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 Astra79.5/100

GPT-6 Astra: Raccoon SVG benchmark
Researcher observations

Expressive animals, a balanced sunset composition and sweeping wake make an appealing illustration. The raccoon rides the dog's back, and the dog's connected foreleg reaches the controls. The compact steering assembly and layered paws are less clearly constructed. Lighting remains mostly flat, with little shadow or sun reflection. Clean contours and purposeful details support strong illustrative execution.

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 Fable 5.1GPT-6 Astra
Prompt & likeness8.5/108.5/10
Anatomy & construction6.5/107.5/10
Space & placement7.0/108.0/10
Light & reflections5.5/106.5/10
Purposeful detail7.0/108.0/10
Artistry & character7.5/108.5/10
Materials & effects6.5/108.0/10
Visual integrity7.5/108.5/10

Pelican

Benchmax control

Outside General and Visual Intelligence.

Claude Fable 5.172.3/100

Claude Fable 5.1: Pelican SVG benchmark
Researcher observations

The pelican reads clearly, with an expressive face, prominent bill and appealing composition. Both legs connect to the body, but the far foot's pedal contact and the wing's steering grip remain unclear. Wheel alignment and background layers are coherent. Clean contours and feather lines give polish, while schematic machinery, limited surface texture and weak directional lighting constrain the finish.

Exact prompt

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

GPT-6 Astra75.8/100

GPT-6 Astra: Pelican SVG benchmark
Researcher observations

The pelican's long bill, flowing scarf and warm coastal palette create a charming, balanced illustration. Wheels, spokes and frame are largely coherent, but neither wing reaches the handlebars, and the rear leg's pedal contact is unclear. Flat lighting and simplified surfaces limit depth despite clean outlines and attractive feather detail.

Exact prompt

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

Compare category scores
CategoryClaude Fable 5.1GPT-6 Astra
Prompt & likeness8.5/108.0/10
Anatomy & construction6.5/106.5/10
Space & placement7.5/107.5/10
Light & reflections6.0/107.0/10
Purposeful detail7.0/108.0/10
Artistry & character7.5/108.5/10
Materials & effects6.0/107.5/10
Visual integrity8.0/108.0/10