STEALTHMARK · HEAD TO HEAD

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Claude Fable 5.1 vs GPT 5.6 Luna

Claude Fable 5.1 scores 13.4 points higher overall (62.1 vs 48.7). Claude Fable 5.1 scores higher on Newton's Mirror, with its largest category advantage in reflections.

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Overall StealthMark

62.1/100
48.7/100

General Intelligence

54.3/100
24.0/100

Visual Intelligence

67.7/100
67.1/100

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 5.6 Luna18.1/100

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

The room enclosure has coherent symmetric perspective, with the overhead panel, sphere and black aligned centrally. The sphere and airborne black occupy substantially lower positions than the reference framing, inconsistent with the prescribed camera aim. The diagonal crimson streak does not establish the required surface transport. Faint wall sphere images provide limited mirrored correspondence, but the shallow floor image, missing receding chains, absent nested sphere imagery and sparse emitter mapping leave most reflection structure unsupported.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Fable 5.1GPT 5.6 Luna
State at 600 ms24.0/2515.0/25
Camera and placement14.0/154.0/15
Reflections48.0/1203.5/120
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 5.6 Luna61.8/100

GPT 5.6 Luna: Selfie SVG benchmark
Researcher observations

Six pale, outward-facing heads and six rounded lobes make the knot recognizable. The central hexagonal opening remains clear. However, broad gray crossing panels flatten the weave, several inner joins resemble capped strips, and sparse oversized scale marks leave the bodies looking more like decorated ribbons than living snakes.

Prompt withheld

This prompt is held back to prevent benchmaxxing.

Compare category scores
CategoryClaude Fable 5.1GPT 5.6 Luna
Prompt & likeness6.5/107.5/10
Anatomy & construction6.5/106.0/10
Space & placement7.5/106.5/10
Light & reflections6.5/105.0/10
Purposeful detail6.0/105.5/10
Artistry & character7.5/106.5/10
Materials & effects6.5/105.0/10
Visual integrity8.0/106.0/10

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 5.6 Luna67.8/100

GPT 5.6 Luna: Beach SVG benchmark
Researcher observations

The warm sunset, palm silhouette and varied beach activities create an appealing, readable composition. Animals, birds and a broad sun reflection satisfy the brief. Drawing remains elementary: angular airborne sea animals lack splash or convincing motion, the crab's claws are awkwardly constructed, and repeated reflection bands suggest a stepped platform. Clean outlines and pleasant colors exceed the anatomical and spatial sophistication.

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 5.6 Luna
Prompt & likeness8.5/108.0/10
Anatomy & construction7.0/106.0/10
Space & placement7.0/106.5/10
Light & reflections7.0/106.5/10
Purposeful detail7.5/106.5/10
Artistry & character8.0/107.0/10
Materials & effects6.5/106.0/10
Visual integrity8.0/107.5/10

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 5.6 Luna63.0/100

GPT 5.6 Luna: Mona Lisa SVG benchmark
Researcher observations

The central portrait, dark clothing, crossed hands and muted landscape clearly evoke Mona Lisa. Replication is limited by the elongated face, conspicuous eyes and simplified smile. Overlapping fingers have uncertain anatomy, while broad gradients and heavy outlines flatten the portrait. The composition and restrained palette remain coherent.

Exact prompt

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

Compare category scores
CategoryClaude Fable 5.1GPT 5.6 Luna
Prompt & likeness6.0/106.5/10
Anatomy & construction5.0/106.0/10
Space & placement6.0/106.5/10
Light & reflections6.0/106.5/10
Purposeful detail5.0/105.5/10
Artistry & character5.5/106.5/10
Materials & effects5.5/105.5/10
Visual integrity6.5/107.0/10

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 5.6 Luna70.8/100

GPT 5.6 Luna: Raccoon SVG benchmark
Researcher observations

Expressive animals, a striped tail and clean outlines make the scene appealing and readable. The raccoon sits convincingly on the dog's back, but the overlapping steering paws are ambiguous and the control stem stops above the hull. Broad wake shapes suggest motion; the glowing sun lacks a corresponding water reflection.

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 5.6 Luna
Prompt & likeness8.5/107.5/10
Anatomy & construction6.5/106.5/10
Space & placement7.0/107.0/10
Light & reflections5.5/106.0/10
Purposeful detail7.0/107.5/10
Artistry & character7.5/107.5/10
Materials & effects6.5/106.5/10
Visual integrity7.5/108.0/10

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 5.6 Luna76.0/100

GPT 5.6 Luna: Pelican SVG benchmark
Researcher observations

A recognizable pelican cyclist with an expressive profile, balanced composition and controlled outlines. Head, neck and torso connect coherently. The bicycle wheels and frame are convincing, but overlapping feet obscure pedal contact, the drivetrain lacks a clear chain, and the wing's handlebar grip is schematic. Atmospheric color succeeds more strongly than directional lighting or material depth.

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 5.6 Luna
Prompt & likeness8.5/108.5/10
Anatomy & construction6.5/107.0/10
Space & placement7.5/107.5/10
Light & reflections6.0/106.5/10
Purposeful detail7.0/107.5/10
Artistry & character7.5/108.0/10
Materials & effects6.0/107.0/10
Visual integrity8.0/108.5/10