STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-5.5 vs Inkling-Small

GPT-5.5 leads Inkling-Small by 8.9 points on StealthMark, 36.5 to 27.6. It leads on 6 of 9 benchmarks, including Latch, and Inkling-Small on 3, including Foresight. GPT-5.5 scores higher on Newton's Mirror, with its largest category advantage in materials and scale.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

36.5/100Overall rank 38/53
27.6/100Overall rank 43/53

General Intelligence

36.6/100
25.5/100

Visual Intelligence

36.3/100
31.1/100

Reasoning efficiency

On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.

Single-step reasoning Result quality weighed against reasoning tokens on a single problem

Multi-step reasoning Result quality weighed against reasoning tokens across connected steps, as in agentic workflows

  • Inkling-Small

Open or local

Open modelApache 2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-5.5
  • Inkling-Small
  • Other models
  • Median

DATASHEET

Specs and pricing

Both take about 1.05M tokens of context.

  • GPT-5.5
  • Inkling-Small
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-5.5: $30$5 inputInkling-Small: No list price
Context windowTokens per request, max output below
GPT-5.5: 1.05MTied128K max outputInkling-Small: 1MTied
Output speedTokens per second, our measurement
GPT-5.5: 193tokens/sInkling-Small: Not measured
SizeTotal and active parameters
GPT-5.5: Not disclosedInkling-Small: 276B12B active
Developer
OpenAIThinking Machines Lab
Released
23 Apr 2026Not published
Origin
United StatesNot published
Input → output
Text, image → textText, image, audio → text
Architecture
Not published42-layer decoder-only transformer with sparse mixture-of-experts feed-forward (6 of 256 routed experts plus 2 shared per token); hybrid local and global attention; natively multimodal with a hierarchical patch image encoder and discrete-token audio

Full datasheets, every price and sourceGPT-5.5 ↗Inkling-Small ↗

Anticipating threats and planning ahead. Collect coins while avoiding ghosts. Ghosts move before the player each turn, and collisions cost a life. 3 levels in sequence, up to 66 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

GPT-5.5 38.7/100Rank 35/492 of 3 levels

2 of 3 played
Foresight: complete playing field
Level 25 ptsTurn 9 / 18

Inkling-Small 30.2/100Rank 29/49

Survived 0 of 3
Foresight: complete playing field
Level 38 ptsTurn 17 / 20

Points per level

LevelGPT-5.5Inkling-Small
Level 1Second Thoughts
17 ptsOut of lives
9 ptsOut of lives
Level 2Pressure Pot
5 ptsOut of lives
6 ptsOut of lives
Level 3Hide or Flight
Not played
8 ptsOut of lives

Cooperative planning and learning from experience. Coordinate two robots to push numbered cores onto matching sockets. Pressure plates hold doors open; moving either robot uses one turn. 5 levels in sequence, up to 152 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

GPT-5.5 71.7/100Rank 16/50

Cleared 5 of 5
Latch: complete playing field
Level 520.6 ptsTurn 27 / 40

Inkling-Small 34.7/100Rank 34/50

Cleared 3 of 5
Latch: complete playing field
Level 518 ptsTurn 40 / 40

Points per level

LevelGPT-5.5Inkling-Small
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.8 ptsCleared
Level 3Relay vault
18.8 ptsCleared
2.8 ptsFinished early
Level 4Passing bay
17.2 ptsClearedFinished early · 1 beacon left
8 ptsFinished early
Level 5Second thoughts
20.6 ptsCleared
18 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

GPT-5.5

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.

Inkling-Small

The sphere's apparent floor support, separate dark feature and broad paint ordering justify partial state credit. The major weakness is the largely missing mirror system: isolated side images and faint floor echoes do not establish repeated virtual rooms or curved spherical mapping. Downward framing, the oversized frontal panel, unresolved paint transport and satin surface appearance remain distinct limitations.

Score breakdown

CategoryGPT-5.5Inkling-Small
State at 600 ms15.0/2514.0/25
Camera and placement6.0/153.0/15
Reflections5.0/1208.0/120
Materials and scale6.0/102.5/10
Floor-damage reward0.0/100.0/10

Benchmark task

A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.

Selfie

Different task instructions

Visual construction and creative interpretation.

The judgment

GPT-5.5

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.

Inkling-Small

The faces and dripping caps communicate a cute mushroom scene, but simple construction and weak spatial relationships limit the result. The defining foot-stamping action is unresolved, the flattering portrait is smaller than its painter, and the requested material contrasts are only partly conveyed.

Score breakdown

CategoryGPT-5.5Inkling-Small
Task & likeness3.0/102.5/10
Anatomy & construction3.0/101.5/10
Space & placement5.0/103.5/10
Light & reflections5.0/103.0/10
Purposeful detail4.5/104.5/10
Artistry & character4.0/103.0/10
Materials & effects4.5/103.5/10
Visual integrity7.0/102.0/10

Benchmark task

GPT-5.5

A pale serpent woven into an interlocking knot tests connected anatomy, repeated structure and readable overlaps. Organic surface detail must work with the overall geometry.

Inkling-Small

Character scenes test expression, anatomy, materials and coherent visual construction.

Mona Lisa

Same task instructions

Precise visual recall and portrait reconstruction.

The judgment

GPT-5.5

The veil, restrained smile, crossed hands and muted landscape establish Mona Lisa references. The oversized frontal face and schematic features weaken likeness and expression, while fingerless tapered hand shapes leave anatomy unresolved. Clean contours and balanced framing provide coherence, but sparse garment detail, broad landscape bands and shallow shading limit the portrait's sophistication.

Inkling-Small

A recognizable but rudimentary Mona Lisa interpretation. Facial shading and subdued colors provide coherence, while the frontal blocklike torso, unresolved wrists, fingerless hands and shallow landscape substantially limit likeness, construction and finish.

Score breakdown

CategoryGPT-5.5Inkling-Small
Task & likeness1.5/102.5/10
Anatomy & construction1.5/102.5/10
Space & placement1.5/103.0/10
Light & reflections2.0/102.5/10
Purposeful detail2.5/102.0/10
Artistry & character1.5/102.5/10
Materials & effects2.0/102.0/10
Visual integrity1.5/103.0/10

Benchmark task

An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.

Beach

Same task instructions

Creativity, perspective and visual beauty.

The judgment

GPT-5.5

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 is underdeveloped: torso and limb connections are unclear, especially in the round-eared foreground figure. The dolphin lacks a convincing splash, and broad reflection bands suggest sunset light without resolving its behavior on water.

Inkling-Small

A recognizable sunset beach with a clear focal sun and appealing color transitions. Connected fish silhouettes and layered scenery establish basic coherence. Primitive figures, ambiguous recreation, sparse descriptive detail and weak grounding limit construction and depth. The aligned reflection supplies a useful lighting cue, but shadows and material effects remain underdeveloped.

Score breakdown

CategoryGPT-5.5Inkling-Small
Task & likeness7.0/103.5/10
Anatomy & construction2.5/103.0/10
Space & placement3.0/103.0/10
Light & reflections3.0/103.0/10
Purposeful detail3.0/103.0/10
Artistry & character3.0/103.0/10
Materials & effects3.0/102.5/10
Visual integrity3.5/102.0/10

Benchmark task

A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.

Ground Truth

Same task instructions

Physical reasoning, light and visual reconstruction.

The judgment

GPT-5.5

This benchmark has not been assessed yet.

Inkling-Small

This benchmark has not been assessed yet.

Benchmark task

A plank, computer mouse and blueberry in a steel room test physical stability, spatial relationships, materials and lighting.

Raccoon

Same task instructions

Scene composition and interacting subjects.

The judgment

GPT-5.5

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.

Inkling-Small

Recognizable animals, readable accessories and an appealing sunset support a coherent basic cartoon. Rounded construction leaves joints, riding support and steering unresolved. Decorative gradients contribute atmosphere, but directional lighting, distinct materials and convincing water displacement are weakly demonstrated.

Score breakdown

CategoryGPT-5.5Inkling-Small
Task & likeness3.5/104.0/10
Anatomy & construction3.0/103.0/10
Space & placement4.5/104.0/10
Light & reflections5.0/105.0/10
Purposeful detail3.5/105.5/10
Artistry & character3.0/104.0/10
Materials & effects5.0/105.0/10
Visual integrity3.0/105.0/10

Benchmark task

A jet-ski scene pairs a canine driver with a raccoon passenger. It tests the placement and contact of interacting subjects, along with vehicle construction.

Pelican

Same task instructions

Subject construction and spatial relationships.

The judgment

GPT-5.5

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.

Inkling-Small

The pelican is immediately recognizable, and its sweeping neck, shaped bill and orderly spokes provide character. Riding remains only partially realized: legs, pedal engagement, steering and seat support cannot be read confidently. Controlled graphic effects add atmosphere, but simplified construction and weak grounding keep the result basic.

Score breakdown

CategoryGPT-5.5Inkling-Small
Task & likeness7.5/104.0/10
Anatomy & construction4.5/103.0/10
Space & placement6.5/103.0/10
Light & reflections6.5/103.0/10
Purposeful detail5.5/104.5/10
Artistry & character5.0/105.0/10
Materials & effects6.0/104.5/10
Visual integrity7.5/103.0/10

Benchmark task

A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.